Wonderware Allen-Bradley ControlLogix I/O Server

Transcription

1 Wonderware Allen-Bradley ControlLogix I/O Server User s Guide Revision B July 2001 Wonderware Corporation

2 All rights reserved. No part of this documentation shall be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the Wonderware Corporation. No copyright or patent liability is assumed with respect to the use of the information contained herein. Although every precaution has been taken in the preparation of this documentation, the publisher and author assume no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein. The information in this documentation is subject to change without notice and does not represent a commitment on the part of Wonderware Corporation. The software described in this documentation is furnished under a license or nondisclosure agreement. This software may be used or copied only in accordance with the terms of these agreements. Wonderware Allen-Bradley ControlLogix I/O Server User s Guide ª 2001 Wonderware Corporation. All Rights Reserved. 100 Technology Drive Irvine, CA U.S.A. (949) Trademarks All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Wonderware Corporation cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. Wonderware and InTouch are registered trademarks of Wonderware Corporation. FactorySuite, Wonderware FactorySuite, WindowMaker, WindowViewer, SQL Access Manager, Recipe Manager, SPCPro, DBDump, DBLoad, HDMerge, HistData, Wonderware Logger, Alarm Logger, InControl, InTrack, InBatch, IndustrialSQL, FactoryOffice, FactoryFocus, License Viewer, SuiteLink, SuiteVoyager and NetDDE are trademarks of Wonderware Corporation. Microsoft, Microsoft Excel, MS-DOS, Windows, Windows NT and Windows 2000 are eigher registered trademarks or tradements of Microsoft Corporation. Allen-Bradley, PLC, PLC-2, PLC-3, and PLC-5 are registered trademarks of Allen-Bradley Company, Inc., A Rockwell International Company.

3 Data Highway, Data Highway Plus, DH, DH+, SLC 500, INTERCHANGE, and Pyramid Integrator are trademarks of Allen-Bradley Company, Inc., A Rockwell International Company.

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5 i Contents Introduction...1 Communication Protocols...1 Accessing Remote Items via the I/O Server...2 Getting Started Quickly with the I/O Server...3 Using Windows NT and Windows ABCIP Main Window...4 View Menu...4 File Menu...5 Configuring the I/O Server...6 Configuring a Topic Definition...7 Topic Definition...7 ABCIP - Topic Definition...8 Configuring the I/O Server Settings...11 Server Settings...11 Configuring Security...13 Security...13 Configuring Logger...14 Set Logger Mode...14 Data Menu...15 ABCIP - Data Monitor...15 Dump Active Data...17 Dump Topic Name Database...18 Accessing I/O Server Help...19 Contents...19 How to Use Help...19 About ABCIP...19 Unsolicited Message Handling...20 What is an Unsolicited Message?...20 Setting up the PLC...21 Setting up the I/O Server and InTouch...23 Error Conditions Inside the PLC...24 Comments About Unsolicited Messages...25

6 ii Wonderware Allen-Bradley ControlLogix I/O Server Item Names PLC-5 Item Naming SLC-500 Item Naming Predefined Item/Point Names UPDATEINTERVAL Item MAXINTERVAL Item STORESETTINGS Item ITEMCOUNT Item ERRORCOUNT Item WRITECOMPLETE Item STATUS Item Monitoring the Status of Communications with a PLC Using the Status Item in Excel Monitoring the Status of Communications with InTouch Using DDEStatus and IOStatus in Excel Reading Values from the I/O Server into Excel Writing Values to the I/O Server from Excel Troubleshooting I/O Server Communication Problems Debugging Communication Between InTouch and an I/O Server Debugging Communication Between SuiteLink and an I/O Server Debugging Communication Between an I/O Server and a PLC... 52

7 1 Wonderware Allen-Bradley ControlLogix I/O Server Introduction The Wonderware Allen-Bradley ControlLogix I/O Server (referred to as the server through the remainder of this user s guide) is a Microsoft Windows application program that acts as a communication protocol server. It allows other Windows application programs access to data in PLCs (also referred to as devices) attached to the DH+ and ControlNet networks through the ControlLogix Gateway. The server requires the Rockwell Software RSLinx OEM package. It can access data in PLC-5, SLC-500 and Logix-5000 Controller (emulating PLC-5 or SLC-500) from Ethernet connected to the ControlLogix Gateway (is this a TM?). While the server is primarily intended for use with Wonderware InTouch (version 3.01 and later), it may be used by any Microsoft Windows program capable of acting as a DDE, FastDDE, or SuiteLink client. Communication Protocols Dynamic Data Exchange (DDE) is a communication protocol developed by Microsoft to allow applications in the Windows environment to send/receive data and instructions to/from each other. It implements a client-server relationship between two concurrently running applications. The server application provides the data and accepts requests from any other application interested in its data. Requesting applications are called clients. Some applications such as InTouch and Microsoft Excel can simultaneously be both a client and a server. FastDDE provides a means of packing many proprietary Wonderware DDE messages into a single Microsoft DDE message. This packing improves efficiency and performance by reducing the total number of DDE transactions required between a client and a server. Although Wonderware's FastDDE has extended the usefulness of DDE for our industry, this extension is being pushed to its performance constraints in distributed environments. NetDDE extends the standard Windows DDE functionality to include communication over local area networks and through serial ports. Network extensions are available to allow DDE links between applications running on different computers connected via networks or modems. For example, NetDDE supports DDE between applications running on IBM compatible computers connected via LAN or modem and DDE-aware applications running on non-pc based platforms under operating environments such as VMS and UNIX. SuiteLink uses a TCP/IP based protocol and is designed specifically to meet industrial needs such as data integrity, high-throughput, and easier diagnostics. This protocol standard is only supported on Microsoft Windows NT 4.0 or higher and Windows 2000.

8 2 Wonderware Allen-Bradley ControlLogix I/O Server SuiteLink is not a replacement for DDE, FastDDE, or NetDDE. The protocol used between a client and a server depends on your network connections and configurations. SuiteLink was designed to be the industrial data network distribution standard and provides the following features: Value Time Quality (VTQ) places a time stamp and quality indicator on all data values delivered to VTQ-aware clients. Extensive diagnostics of the data throughput, server loading, computer resource consumption, and network transport are made accessible through the Microsoft Windows NT and Windows 2000 operating system Performance Monitor. This feature is critical for the scheme and maintenance of distributed industrial networks. Consistent high data volumes can be maintained between applications regardless if the applications are on a single node or distributed over a large node count. The network transport protocol is TCP/IP using Microsoft s standard WinSock interface. Accessing Remote Items via the I/O Server The communication protocol addresses an element of data in a conversation that uses a three-part naming convention that includes the application name, topic name and item name. The following briefly describes each portion of this naming convention: application name topic name The name of the Windows program (server) that will be accessing the data element. In the case of data coming from or going to Allen Bradley equipment via this server, the application portion of the address is ABCIP. Meaningful names are configured in the server to identify specific devices. These names are then used as the topic name in all conversations to that device. For example, ABPLC. Note You can define multiple topic names for the same device (PLC) to poll different points at different rates. item name A specific data element within the specified topic. For example, when using this server, an item can be a relay, timer, counter, register, etc., in the PLC. Note The item/point names are predefined by the server. The term "point" is used interchangeably with the term "item" in this user's guide. For more information on item/point names, see the "Item Names" section in this user's guide.

9 Getting Started Quickly with the I/O Server 3 Getting Started Quickly with the I/O Server This section briefly describes the procedure required to install and prepare the Wonderware Allen-Bradley ControlLogix I/O Server for use. Detailed descriptions of each step can be found in the user's guide provided by Allen-Bradley and in later sections of this user's guide. Using Windows NT and Windows Install the Ethernet adapter and TCP/IP software following the instructions provided by the manufacturer. 2. Install and configure the Rockwell Software RSLinx OEM package. This package is provided by Rockwell Software, Inc. 3. Install the Wonderware Allen-Bradley ControlLogix I/O Server for Windows NT or Windows 2000 by running the SETUP.EXE program on the server program disk. 4. Reboot the computer and restart Windows NT or Windows Start the server. (Select the server icon from the server s program group.) 6. On the Configure menu, click Topic Definition to configure topics for the PLCs. 7. The server is now ready for use.

10 4 Wonderware Allen-Bradley ControlLogix I/O Server ABCIP Main Window Double-click on the server s icon to start. When the server starts, the main window will appear: The current configuration file and its full path are displayed in the main window title bar. If any topics are active, they will appear in the client area of this window.view Menu The View menu has two options that change the appearance of the main window, both are enabled or disabled by selecting the respective menu item. A check next to the option indicates the option is enabled. The Toolbar option adds (when enabled) or removes the toolbar (small buttons) located below the server menus. The Status Bar option adds (when enabled) or removes the status indication bar located at bottom of window. The main window shown above has both options enabled. The main window shown below has both options disabled.

11 File Menu 5 File Menu File menu options deal with loading and saving the internal topic configuration database. New Clears the internal topic database for a new topic configuration. This menu is disabled when the server is active. Open Replaces the internal topic database with the information contained in the user selected topic configuration file. This file is automatically loaded the next time the server is started. This menu is disabled when the server is active. Save As Saves the internal topic database under a new name. This command is only needed if you want to save the configuration under a different name. If you edit the internal topic database, the data is stored automatically in the current configuration file. This menu is disabled when the server is active. Exit Terminates the server.

12 6 Wonderware Allen-Bradley ControlLogix I/O Server Configuring the I/O Server Once the server has been installed, some configuration is required. Configuring the server automatically saves the data in a configuration file. If no configuration file is selected, the user is prompted to select a filename. To access the options used for the various configurations, open the Configure menu: Note If any of the options appear grayed, then these options are not available with this software version.

13 Configuring a Topic Definition Configuring a Topic Definition 7 Use the Topic Definition option from the Configure menu to create new, modify, or delete topic definitions. One or more topic definitions must exist for each PLC that the server will communicate with. Each topic definition must contain a unique name for the PLC associated with it. When this option is selected, the Topic Definition dialog box will appear: Topic Definition Note Once topics have been defined, their names will be listed in the Topics section of this dialog box. Click this button to close the dialog box and accept any new definitions, modifications or deletions made. To modify or view an existing topic definition, select its name in the list and click on this button. The ABCIP - Topic Definition dialog box (described below) will appear displaying the selected topic definition. To delete an existing topic definition, select its name in the list and click on this button. A message box will appear prompting you to confirm the deletion. To add a new topic definition, click on this button. The ABCIP - Topic Definition dialog box will appear:

14 8 Wonderware Allen-Bradley ControlLogix I/O Server Note If any of the options appear grayed, then these options may not be available with this software version. ABCIP - Topic Definition Enter a unique name for the PLC in this field, for example ABPLC. Note When communicating with InTouch, this exact name is used as the topic name in the Access Name definition. Select the PLC type for this topic definition.

15 Configuring a Topic Definition 9 Select the Connect Type for this topic definition. Available connection types are as follows: 1756-ENET 1756-CNB: Connect to PLCs on ControlNet from Ethernet ENET 1756-DHRIO: Connect to PLCs on DH+ from Ethernet ENET Logix5550: Connect to Logix5550 Controller from Ethernet. Remote ControlNet: Connect to remote ControlNet port from Ethernet. Note This connect type is similar to the 1756-ENET 1756-CNB type but allows the user to manually construct the ControlNet path. Select or type in the driver name configured in RSLinx for the selected Connect Type. If RSLinx has not been loaded and the select button is pressed, the user will be prompted to load RSLinx for browsing. Select the station number of the ControlNet module or PLC on the local ControlNet network. Configure the Gateway outbound module (for example, 1756-CNB, 1756-DHRIO) or Logix5550 Controller in the ControlLogix Gateway. Link ID is needed if the outbound network is DH+ and unsolicited messages are expected. Select the station number of the PLC on the remote network. Enter the ControlNet Path if Remote ControlNet is specified as the Connect Type, otherwise this field is read only.

16 10 Wonderware Allen-Bradley ControlLogix I/O Server Check this box to enable client access to the update interval. If this box is checked, a client can read and write the update interval on this topic through the predefined item name UPDATEINTERVAL. If this box is not checked, the client can only read the update interval. Note The actual update interval for the slowest item on this topic can be read through the predefined item name MAXINTERVAL. This gives you an indication of the performance of your configuration during operation. Enter the maximum number of consecutive discrete values to be read at one time. The Discrete Read Block Size value can be any integer between 8 and 1920 that is a multiple of 8, for example, 8, 24, 32, 80, etc. The maximum for a SLC-500 is 320. Enter the maximum number of consecutive registers to be read at one time. The Register Read Block Size value can be any integer between 1 and 120. The maximum for a SLC- 500 is 40. Enter the frequency (in milliseconds) that the server will read (poll) the items/points associated with this topic. (Enter a zero in this field when configuring a topic for Unsolicited Messages, this in effect disables periodic polling.) Note Different items/points can be polled at different rates by defining multiple topic names for the same PLC and setting different update rates for each topic. Enter the amount of time (in seconds) that the PLC will be given to reply to commands from the server. Note This timeout is sustained only when the PLC fails to respond. When the PLC is responding normally, there is no penalty. The default value of 12 seconds should be sufficient for most configurations.

17 Configuring the I/O Server Settings Configuring the I/O Server Settings 11 Use the Server Settings option from the Configure menu to change the protocol timer, network using Wonderware NetDDE, change the default configuration file path, or to enable the server to start automatically as a Windows NT or Windows 2000 service. Note When configuring the server on Windows NT or Windows 2000, the user must be logged on with system administrator privileges. This will ensure that updates to the system registry may be performed. When the Server Settings option is selected, the Server Settings dialog box will appear: Server Settings Enter the frequency (in milliseconds) that the server is to check for data to process. This should be approximately two to four times faster than the fastest rate desired to update data from the equipment. Note The default protocol timer tick value will vary between servers. Select this option if you are networking using Wonderware NetDDE. To create a new default configuration file, enter the complete path for the directory in which the file is to be saved in this field. This new path will automatically be written to the WIN.INI file and the server will use this path to load its configuration file the next time it is started.

18 12 Wonderware Allen-Bradley ControlLogix I/O Server Enabling this option will cause the server to start as a Windows NT or Windows 2000 service. Windows NT and Windows 2000 offers the capability of running applications even when a user is not logged on to the system. This is valuable when systems must operate in an unattended mode. Enabling this option and rebooting the system will cause the server to run as a Windows NT or Windows 2000 service. However, to view configuration information or to reconfigure the server, the user must log on to the system. Any server related problems that may arise such as missing adapter cards, licensing failures or device drivers not loading will not be visible to the user until a log on is performed. Disabling this option and rebooting the system will cause the server to run as a Windows NT or Windows 2000 application program once again. Note It is highly recommended that the server is configured and communicating successfully prior to running it as a Windows NT or Windows 2000 service. Click Cancel to close the dialog box without saving changes. Click OK to close the dialog box. Note You must restart the server for the changes to take effect.

19 Configuring Security Configuring Security 13 Use the Security option from the configure menu to control server configuration changes. Security When the server is not active (no clients connected), all server configuration options are available for modification. The default setting for Allow configuration while topics are active is disabled. When disabled, all topics are viewable (but locked against changes) via the ABCIP - Topic Definition dialog box while the server is active (a client is connected). Enable Allow configuration while topics are active to allow write access to some parameters of the topic configuration while the server is active. This server supports write access to the Update Interval, Reply Timeout, and Enable Access to Update Interval parameters. You cannot add, delete, rename or change other parameters of a topic configuration. Click OK to save changes and close the dialog box. Click Cancel to close the dialog box without saving changes.

20 14 Wonderware Allen-Bradley ControlLogix I/O Server Configuring Logger Use the Logger option from the configure menu to set the working logger mode of the server. The options controlled by this dialog box are NOT retained in the configuration file. Set Logger Mode Note Each time the server starts, the logger mode will default to Errors. Select Off to disable normal server logging. Select Errors for normal operation logging to the Wonderware Logger. Select Trace to log errors and all activation/deactivation activities. Select All to log all activities including single item value updates. Enable Show protocol to add PLC communication message data to the selected logger mode. Click OK to use changes and close the dialog box. Click Cancel to close the dialog box without changing current settings. Note When logging activity increases, the server s performance degrades.

21 Data Menu 15 Data Menu The Data menu contains two commands, Monitor and Dump Active Data, that are used for diagnostic purposes during runtime (when a client is attached). The remaining command, DB Dump, is used to transfer the internal topic database to InTouch. Note If any of the options appear grayed, then these options may not be available with this software version. ABCIP - Data Monitor Use the Monitor option from the data menu to display and record topic and item statistics for a single, active topic. The information is updated as it changes. This is a useful tool for tracking down errors, for determining performance and to validate item values. When the Monitor option is selected, the ABCIP - Data Monitor window will appear.

22 16 Wonderware Allen-Bradley ControlLogix I/O Server This drop down list box allows you to select any of the active topics. A preceding * indicates that at least one item in this topic has an error while a preceding # indicates bad communication status. This field displays the current configured update interval of the topic. This value changes whenever the value is modified. The displayed value is the predefined UPDATEINTERVAL item value. This field displays the current update interval of the slowest item of the topic. This value is measured for each poll cycle and each received cyclic service indication. If this value drastically differs from the desired update interval the communication media is not fast enough to satisfy the load. Note You can create an InTouch performance meter by displaying the predefined UPDATEINTERVAL and MAXINTERVAL (Longest Interval) item values. graphically for each topic. If the topic is configured to Enable access to update interval, then you can even tune the bus performance conveniently from InTouch. This field displays the number of active items and the number of items with errors (in parenthesis). If you check this box, only items with errors will be displayed. The item list box displays the quality, time, value, and name of each active item. Click on an item line to view additional item properties: Click OK to return to the ABCIP - Data Monitor dialog box.

23 Data Menu 17 Click Dump to dump the contents of the ABCIP - Data Monitor window into an ASCII text file. The resulting file can be loaded into Excel or any standard text editor. All columns are separated by tabs. After the dump is complete, a message box containing the newly created ASCII text file name is displayed. The server automatically generates the ASCII text file name and sets the files location using the following pattern: <current working directory>\datmonxx.txt Where XX is a two digit number between 00 and 99. The server increments the number each time a file is dumped. Note Existing files with the same name are erased. Click OK to return to the ABCIP - Data Monitor dialog box. Note Monitoring the items might affect the server performance. Dump Active Data Use the Dump Active Data option from the data menu to dump server, topic, and item statistics for all topics with active items into an ASCII text file. The resulting file can be loaded into Excel or any standard text editor. All columns are separated by tabs. When the Dump Active Data option is selected, the Dump Active Data dialog box will appear. Enable Errors only option to dump topics with errors. Click OK to start the dump. Click Cancel to close dialog without creating a dump file. After the dump is complete, a message box containing the newly created ASCII text file name is displayed.

24 18 Wonderware Allen-Bradley ControlLogix I/O Server The server automatically generates the ASCII text file name and sets the files location using the following pattern: <current working directory>\datdmpxx.txt Where XX is a two digit number between 00 and 99. The server increments the number each time a file is dumped. Note Existing files with the same name are erased. Dump Topic Name Database Use the DB Dump option from the data menu to dump the internal topic name database into a CSV format file. Wonderware s DBLoad utility can use the resulting file to automatically generate InTouch Access Names. Create the file by selecting a directory and filename using the standard dialog shown below:

25 Accessing I/O Server Help Accessing I/O Server Help 19 The Help menu contains three options that are used to access help for the server. The following briefly describes the Help menu options. Contents This option is used to display the table of contents for the Help file. How to Use Help This option is used to access a list of basic instructions for using the Help file. About ABCIP This option is used to access miscellaneous information regarding the server, such as the software version, the copyright information, license information, etc. Your FactorySuite system license information can be viewed through the license viewing utility that is launched from the About dialog box. For more information on the licensing viewing utility, see your online FactorySuite System Administrator s Guide.

26 20 Wonderware Allen-Bradley ControlLogix I/O Server Unsolicited Message Handling Wonderware's servers are based on the concept of polling a hardware device for information. This polling is driven by a need, which is expressed in the form of a requests from one or more clients. Once a particular piece of information has been requested by a client, the server formulates its own request and sends that request to the hardware device. The server then waits for a response to its request. Once the information has been received, the server passes that information back to the client, and repeats the process until all clients have ceased requesting information. The rate at which the server will poll a particular device for a specific piece of information is defined in the topic definition, inside the server, using a parameter called the Update Interval. When setting this parameter, there is always a trade-off between the update speed of the topic and the resulting decrease in system responsiveness. Since you more than likely want very fast response, the temptation is to set the Update Interval to a value close to 0 milliseconds. However, if every point is polled at this rate, the entire system will suffer due to slow response time. Therefore, you should compromise, and set the Update Interval to a more reasonable value. You could also create multiple topics for each device, setting the Update Interval to different values, then assign different items to different topics depending on how quickly the values change, and how quickly you want to see an update of those changes. An item may be very important, but change very infrequently, e.g., alarm bits. You may require very fast updates of alarms when they do change, but realistically you may only see them change once a week, or once a day at best. Because you do not know when this may happen, you are forced to set the Update Interval to some small value, approaching 0 milliseconds. That is, until now! What is an Unsolicited Message? In the world of PLCs and servers it is obvious, to even the most casual user, that a PLC will know when a critical event has occurred before the server will have a chance to poll for that data. Therefore, it would seem natural that if a critical event occurs, the PLC should have the capability to inform the server immediately, without having to wait for the server to poll it. This is the role of an unsolicited message. Once a PLC has determined that a critical condition exists, it can generate a "reply" message to a poll which never occurred. In other words, it can answer the server's question before the server has a chance to ask it. The following Allen-Bradley processors are capable of producing unsolicited messages that the Wonderware I/O Servers can understand. Specifically, the PLC-5 and SLC-500.

27 Setting up the PLC Unsolicited Message Handling 21 This section explains how to set up the PLC to send unsolicited messages. To illustrate the ladder logic required to perform this function, we will use the example below. This was tested with a PLC 5/10 processor, connected to a Data Highway Plus with the 5/10 and a S-S Technologies 5136-SD card connected to it. Note The text and illustrations below provide you with one example of how a Wonderware Allen-Bradley I/O Server and the Allen-Bradley hardware need to be configured to get unsolicited messages from the PLC to the server. This same concept, changed only slightly, is compatible with any of the Wonderware Allen-Bradley I/O Servers. Inside Station 02 (the PLC 5/10) the following rungs were entered: When viewing the MSG instruction (second line, last instruction in diagram above) with the Allen-Bradley 6200 software, the MSG instruction parameters have the following values: Parameter Select Communications Command: PLC-5 Typed Write PLC Data Table Address: N12:190 Size in Elements: 1 Local/Remote: Local Remote Station: N/A Link ID: N/A Remote Link Type: N/A Local Node Address: 1 Destination Data Table Address: N12:190

28 22 Wonderware Allen-Bradley ControlLogix I/O Server Communications Command This must be a Write. A Read would not make sense here. PLC Data Table Address The memory address of the value that will be sent to the Wonderware I/O Server. This address refers to the location inside the PLC. (For more information, see the "Destination Data Table Address".) Size In Elements Indicates how many elements will be moved per message, starting at the PLC Data Table Address previously defined. An element's actual size depends on the type of data being handled. For example, a single element of type N (Integer) is 16 bits (two bytes) long. Whereas, a single element of type F (Floating Point) is 32 bits (two words) long. Local/Remote Defines if the destination DH+ station (in this case, the server) is on the same DH+ as this PLC. If the server is on the same DH+ as the PLC, then the addressing is Local, otherwise, the message must be sent via a Bridge. If this is the case, then Remote addressing would be selected. Remote Station, Link ID, and Remote Link Type These settings specify the type of Data Highway the Remote Link is. Typical settings include DH, DH+, DHII, etc. This link must have a number associated with it, this number is referred to as the Link ID, or the Link Number. Typical settings are 0, 1, 2 or 3. The Remote Station is the station number on the Remote Link to which this message will be sent. Local Node Address Defines the Destination station's address on the DH+, in both Local and Remote situations.

29 Destination Data Table Address Unsolicited Message Handling 23 The address into which the value defined by the PLC Data Table Address will be placed. In the case of unsolicited messages to the server, this is the address that has been entered into the Item field of a particular Tagname inside InTouch. For example, you may have a tag called: TankLevel with the item, N12:190. The item specified would be the address used for this parameter. In most cases, the PLC Data Table Address and the Destination Data Table Address do not need to be the same. To reduce confusion when debugging the system, we recommend that they be identical. Setting up the I/O Server and InTouch This section briefly describes how to set up the server and InTouch to accept unsolicited messages. The following topic was defined in the server: Topic Name: Unsolicited_PLC2 Card: SD:0 PLC Station Address: 02 (Octal) Update Interval: 0 The following Access Name was defined in InTouch: Access Name: Application/Server: Topic: Wait For Change: Advise All Items: Unsolicited_PLC2 SS5136SD Unsolicited_PLC2 Checked Checked Note If a PLC generates an unsolicited message and the destination tagname is not advised (active inside InTouch), the server will generate an error message. To avoid this, create a separate Access Name with the Advise all items option enabled, and associate only those tags that will be receiving unsolicited messages to it. By doing this, all unsolicited message items will be advised and will receive the unsolicited data, even if the tagname is not used in a visible window. The following tagname was defined in InTouch: TagName: TankLevel TagType: Integer AccessName: Unsolicited_PLC2 Item: N12:190 Note If Advise only active items is checked and the tag is displayed on the screen, it will be advised. When this occurs, the server will store that tagname as an item that needs to be polled regularly from the PLC. For example, if the update interval was set to five minutes (configured in the topic definition), then every five minutes the server will send out a request for the current value of N12:190 to the PLC. The PLC will respond, returning the value inside N12:190, in our example above. This is a Normal Polling Cycle.

30 24 Wonderware Allen-Bradley ControlLogix I/O Server At the same time, the PLC is constantly monitoring the value of the TankLevel, stored in register N12:190. If this value grows larger than 128, the PLC logic will initiate the MSG instruction. The MSG instruction will take the value of N12:190 and write it to the server. The server will see the incoming message and attempt to match the PLC station address defined in the server. It will also try to match the Destination Data Table Address to one that is currently being polled for that particular PLC address. If this matching procedure succeeds, the value of that tag will be updated with the value sent from the PLC's MSG instruction. Error Conditions Inside the PLC The Allen-Bradley 1785 PLC-5 processors have a separate CPU to handle Data Highway Plus communications. This processor works independently of the program scan. This is an advantage, since the program scan is not inhibited by lengthy Data Highway Plus command queues. This means that the status bits and words associated with the MSG instruction will be updated synchronously to the program scan. If an error bit is false when the program begins to scan, half way through the rungs, the bit may go high. Inside the Allen-Bradley PLC, it is important to properly handle error conditions with a MSG instruction. If a MSG instruction's.er bit goes high, it is advisable to stop sending MSGs for a period of 15 to 60 seconds. Then, send another MSG, waiting for a.dn bit before attempting to resume normal communication. If this is not done, the MSG instruction will default to a "slow mode" of one MSG every 15 seconds. If these MSGs continue to be unacknowledged by the server, there is a chance the PLC will halt communication with the server until the MSG instruction is reset. This is something that cannot be done from the Wonderware I/O Server since the PLC may no longer be communicating with it.

31 Unsolicited Message Handling 25 Comments About Unsolicited Messages 1. In general, unsolicited messages should be used only on rare occasions, not as the normal mode of data transmission. 2. A MSG instruction inside a PLC should never be placed in 'continuous' mode. This will cause the MSG instruction to generate outgoing messages as quickly as possible, continuously, regardless of the state of the instructions ahead of it. Therefore, even if the Bit B10:0/14 is FALSE, if the.co bit (Continuous Bit) is set in the MSG instruction, the MSG instruction will continue to generate messages as quickly as possible until either the processor has been placed into PROGRAM mode, or the.co bit is toggled off. 3. Read the Allen-Bradley manual, publication , April 1992 for more information about the MSG instruction inside the 1785 PLC-5 s. Other PLC s manuals also have specific information regarding generating a MSG instruction in the Ladder Logic. Note The PLC-2 was never designed to allow communication on the DH. It has a communications module, the 1771-KA2, which allows the PLC-2 to sit on the DH. The PLC-2 manual therefore has no mention of the messaging capabilities of the PLC-2. The manual for the 1771-KA2 has all the information you ll need to set up an unsolicited message from the PLC If a PLC generates an unsolicited message and the destination tagname is not advised (active inside InTouch), the server will generate an error message. To avoid this, create a separate Access Name with the Advise all items option enabled, and associate only those tagnames that will be receiving unsolicited messages. By doing this, all items will be advised and will receive the unsolicited data, even if the tagname is not used in a visible window.

32 26 Wonderware Allen-Bradley ControlLogix I/O Server Item Names The Wonderware Allen-Bradley ControlLogix I/O Server supports item names that follow the conventions described for PLC-5 and SLC-500 PLCs. PLC-5 Item Naming The general format of item names for data from 1785 PLC-5 controllers matches the naming convention used by the programming software. The format is shown below. The parts of the name shown in square brackets ([]) are optional. [$] X [file] : element [.field] [/bit] $ Purely optional. X Identifies the file type. The table below summarizes the valid file types, the default file number for each type and the fields allowed (if any): X File Type Default File #.Fields O Output 0 I Input 1 S Status 2 B Binary 3 T Timer 4.PRE.ACC.EN.TT.DN C Counter 5.PRE.ACC.CU.CD.DN.OV.UN R Control 6.LEN.POS.EN.EU.DN.EM.ER.UL.IN.FD N Integer 7 F Floating Point 8 A ASCII none D BCD none ST ASCII String* none.len PD PID* none.adrf.adre.bias.ca.cl.ct.db.do.dvdb.dvn.dvna.dvp.dvpa.en.err.ewd.ini.kd.ki.kp.maxi.maxo.maxs.mini.mino.mins.mo.olh.oll.out.pe.pv.pvdb.pvh.pvha.pvl.pvla.pvt.so.sp.spor.swm.tie.upd SC SFC Status* none.dn.er.fs.ls.ov.pre.sa.tim BT Block Transfer* (Read Only) none.en.st.dn.er.co.ew.nr.rw.to.rlen.dlen.file.elem * Available only on certain PLC-5 models. Check the Processor Manual for the model being used.

33 Item Names 27 file File number (0-999 decimal). File 0 must be Output, file 1 must be Input and file 2 must be Status. element Element number within the file. For Input and Output files it must be between 0 and 777 octal. For all other file types, it must be between 0 and 999 decimal..field Valid only for Counter, Timer, Control, ASCII String, PID, SFC Status, and Block Transfer files. Refer to the previous table. /bit Valid for all file types except ASCII String and Floating Point. For Input and Output files it must be between 0 and 17 octal. For all other file types it must be between 0 and 15 decimal. Output File Items O[n]:rg[/b] "n" represents the file number is optional and if specified, must be zero. "r" indicates the rack number (octal). "g" indicates the I/O group (octal). "b" specifies the bit (0-17 octal). "/b" may be omitted if necessary to treat the I/O group as a numeric value. Examples: O0:0/0 $O:37/17 O:3 4BCD (for 16-bit 7-segment display) Input File Items I[n]:rg[/b] "n" represents the file number is optional and, if specified, must be one. "r" indicates the rack number (octal). "g" indicates the I/O group (octal). "b" specifies the bit (0-17 octal). "/b" may be omitted if necessary to treat the I/O group as a numeric value. Examples: I1:0/0 I:37/17 I:3 4BCD (for 16-bit thumbwheel input)

34 28 Wonderware Allen-Bradley ControlLogix I/O Server Status File Items S[n]:e[/b] "n" represents the file number is optional and, if specified, must be two. "e" indicates the element number in the file. "b" is optional. If specified, indicates the bit (0-15 decimal). Note Refer to the 1785 PLC-5 Family Processor Manual (Allen- Bradley Publication ) for a complete description of status file information. Examples: $S:18 low status bit) Binary File Items B[n]:e/b or B[n]/m 2 may be between 0 and Examples: B3/15999 (same bit as B:999/15) B:6/4 (same bit as B/100) Timer File Items T[n]:e[.f][/b] "n" represents the file number and is optional. If not specified, it is assumed to be four. If specified, the file number must be between 3 and 999 decimal. "e" specifies the element number (three words per element) within the Timer file. It must be between 0 and 999 decimal. "f" identifies one of the valid Timer fields. The valid fields for Timer Files are listed in the table. If ".f" is omitted, it is assumed to be the word containing the status bits. "b" is optional and is normally not used. All of the fields of a timer can be accessed by specifying the ".f" fields. However, it is possible to use "/b" to single out a bit in the.pre or.acc fields (which are words). For Timer files, the bit number must be between 0 and 15 decimal. Examples: T4:0.ACC T4:0.DN T4:1.PRE

35 Item Names 29 Counter File Items C[n]:e[.f][/b] "n" represents the file number and is optional. If not specified, it is 0 and 15 decimal. Examples: C5:0.ACC C5:3.OV C5:1.PRE Control File Items R[n]:e[.f][/b] "n" represents the file number and is optional. If not specified, it is assumed to be six. If specified, the file number must be between 3 and 999 decimal. "e" specifies the element number (three words per element) within the Control file. It must be between 3 and 999 decimal. "f" identifies one of the valid Control fields. The valid fields for Control files are listed in the table. If ".f" is omitted, it is assumed to be the word containing the status bits. "b" is optional and is normally not used. All of the fields of a Control file can be accessed by specifying the ".f" fields. However, it is possible to use "/b" to single out a bit in the.len or.pos fields (which are words). If specified, it indicates the bit (0-15 decimal). Examples: R6:0.LEN R6:3.EM R6:1.POS Integer File Items N[n]:e[/b] Examples: N7:0 N7:0/15 N7:3 "n" represents the file number (optional). If not specified, it is assumed to be seven. If specified, the file number must be between 3 and 999 decimal. "e" specifies the element number within the Integer file. It must be between 0 and 999 decimal. "b" is optional. If specified, it indicates the bit (0-15 decimal).

36 30 Wonderware Allen-Bradley ControlLogix I/O Server Floating Point File Items F[n]:e Examples: F8:0 F8:3 ASCII File Items An:e[/b] An:x-y "n" represents the file number (optional). If not specified, it is assumed to be eight. If specified, the file number must be between 3 and 999 decimal. "e" specifies the element number within the Floating Point file. It must be between 0 and 999 decimal. "n" represents the file number (NOT optional) and must be between 3 and 999 decimal. "e" specifies the element number within the ASCII file. It must be between 0 and 999 decimal. Each element in an ASCII file contains two ASCII characters. "b" is optional. If specified, indicates bit (0-15 decimal). "x" and "y" also specify element numbers. In this form, the item is an ASCII string occupying element "x" through element "y". Each element contains two ASCII characters. The first character is the high order byte and the second is the low order, etc. Note If reading only one word as a two-character string, the range must be "x-x." For example, A20:3-3. Examples: A20:3 A10:0/0 A9:0-19 (40-character ASCII string)

37 Item Names 31 BCD File Items Dn:e[/b] Examples: D20:3 D10:0/3 ASCII String Section Items STn:e[.f] Examples: ST9:0 ST9:900 ST9:900.LEN "n" represents the file number (NOT optional) and must be between 3 and 999 decimal. "e" specifies the element number within the BCD file. It must be between 0 and 999 decimal. Each element in a BCD file contains a number between 0 and "b" is optional. If specified, it indicates the bit (0-15 decimal). "n" represents the file number (NOT optional) and must be between 9 and 999 decimal. "e" specifies the element number within the String file. It must be between 0 and 999 decimal. Each element in a String file contains an ASCII string with a maximum length of 82 characters. "f" identifies the following ASCII string field:.len. If ".f" is omitted, it is assumed to be the string.

38 32 Wonderware Allen-Bradley ControlLogix I/O Server Block Transfer Section Items BTn:e[.f][/b] Examples: BT9:0.EN BT9:3.RLEN BT9:3.FILE "n" represents the file number (NOT optional) and must be between 9 and 999 decimal. "e" specifies the element number (three words per element) within the Block Transfer file (0 to 999 decimal). "f" identifies one of the valid Block Transfer fields. The valid fields for Block Transfer items are listed in the table. If ".f" is omitted, it is assumed to be the word containing the status bits. "b" is optional and is normally not used. All of the fields of a Block Transfer can be accessed by specifying the ".f" fields. However, it is possible to use "/b" to single out a bit in the.file or.elem fields (which are words). For Block Transfer files, the bit number must be between 0 and 15 decimal. Note Block Transfer files are read only.

39 Item Names 33 PID Section Items PDn:e[.f][/b] Examples: PD9:2.SP PD9:3.OLH PD9:0.INI SFC Status Section Items SCn:e[.f][/b] Examples: SC9:0 SC9:0.PRE SC9:0.SA "n" represents the file number (NOT optional) and must be between 9 and 999 decimal. "e" specifies the element number within the PID file. It must be between 0 and 999 decimal. "f" identifies one of the valid PID fields. The valid fields for PID files are listed in the table. If PID field.addr is needed, use.adre for element and.adrf for file. "b" is optional and is normally not used. All of the fields of a PID can be accessed by specifying the ".f" fields. If specified, it indicates the bit (0-15 decimal). Warning Access to PID files may degrade the server's performance due to the extreme size of the PID element (82 words each). If accessing only a few PIDs at a time, performance will not be greatly affected. If accessing a few fields of many PIDs at once, it may be faster to move the needed fields to an intermediate file (Floating Point or Binary) and let the server access the intermediate files. "n" represents the file number (NOT optional) and must be between 5 and 999 decimal. "e" specifies the element number within the SFC Status file. It must be between 0 and 999 decimal. "f" identifies one of the valid SFC fields. The valid fields for SFC files are listed in the table. "b" is optional and is normally not used. All of the fields of a SFC can be accessed by specifying the ".f" fields. For SFC Status items, the bit number must be between 0 and 15 decimal.

40 34 Wonderware Allen-Bradley ControlLogix I/O Server SLC-500 Item Naming The general format of item names for data from SLC-500 controllers matches the naming convention used by the programming software. The format is shown below. (The parts of the name shown in square brackets ([]) are optional). [$] X [file] : element [.field] [/bit] $ Purely optional. X Identifies the file type. The table below summarizes the valid file types, the default file number for each type and the.fields allowed (if any): X File Type Default File.Fields O Output 0 I Input 1 S Status 2 B Binary 3 T Timer 4.PRE.ACC.EN.TT.DN C Counter 5.PRE.ACC. CU.CD.DN.OV.UN.UA R Control 6.LEN.POS.EN.DN.ER.UL.IN.FD N Integer 7 F Floating Point* 8 A ASCII* none ST ASCII String* none * Available only on certain SLC500 models. Check the Processor Manual for the model being used. file File number must be decimal. File 0 must be Output, file 1 must be Input, file 2 must be Status. element Element number within the file. For Input and Output files it must be between 0and 30 decimal. All other file types, it must be between 0 and 255 decimal..field Valid only for Counter, Timer and Control files, see table above. /bit Valid for all file types except ASCII String and Floating Point. Must be 0-15 decimal.

41 Item Names 35 Output File Items O[n]:e.s[/b] Examples: "n" represents the file number and is optional. If not specified, it is assumed to be zero. "e" indicates the element number in the file. "s" indicates the sub-element number (0-255). "b" specifies the bit (0-15 decimal.) "/b" may be omitted if necessary to treat the I/O group as a numeric value. O0:0/0 $O:2/15 O:3 4BCD (for 16-bit 7-segment display) Input File Items I[n]:e.s[/b] Examples: "n" represents the file number and is optional. If not specified, it is assumed to be one. "e" indicates the element number in the file. "s" indicates the sub-element number (0-255). "b" specifies the bit (0-15 decimal.) "/b" may be omitted if necessary to treat the I/O group as a numeric value. I1:0/0 I:2/15 I:3 4BCD (for 16-bit thumbwheel input)

42 36 Wonderware Allen-Bradley ControlLogix I/O Server Addressing SLC I/O Modules The elements (words) in I/O modules are mapped into a memory table. If the Analog I/O modules are being used, then the point naming will differ from the point naming in the programming software. The server item name must be computed from the sum total of words used by the previous input or output blocks. The operator can use the programming software to look at the memory map of the I file or O file to verify your address. If the address is unsure, or if the PLC configuration is likely to change, copy the points in question to the N table or B table and access the data from there. The naming conventions used in the Allen-Bradley programming software are not supported by the Wonderware Allen-Bradley ControlLogix I/O Server. The addressing convention is similar to that of the PLC-5 family processors. To derive the correct address for each I/O point, use the following. Diagram system Addressing of the I/O points begins by drawing a schematic of the system. The figure below is a diagram of the SLC 5/02 system. The far left unit is the power supply. From left to right, the modules are: 1747-L524 SLC 5/02 Module Processor 1746-IA8 8 point 120VAC input module 1746-OA16 16 Point 120VAC output module 1746-IA16 16 point 120VAC input module 1746-NI4 4 point 20mA analog input module 1746-NO4I 4 point 20mA analog output module A8 8 point 120VAC input module 1746-IB32 32 point DC input module