INSTRUCTION SHEET. USB to RS485 Isolated Converter Kit. Specifications Specifications are subject to change without notice.

Transcription

1 INSTRUCTION SHEET Specifications Specifications are subject to change without notice. Power Temperature Range Isolation Communications USB (<100 ma) 0 to 70 C (0 to 160 F) 200 V RMS Isolated USB to RS485 Settings Baud Rates of 1200, 2400, 4800, 9600, 19200, 38400, 57600, Shipping Weight 0.5 kg (1 lb) Introduction This instruction sheet provides information on installation and use of the B&B Electronics USOTL4 USB to RS485 (Cat. No ) converter in light industrial environments with various Hach process instruments. To use this data converter in heavy industrial locations, see Using the USB to RS485 Isolated Data Converter in Heavy Industrial Locations on page 6. The converter can be configured to support either a 2-wire (Half duplex) or 4-wire (full duplex) RS485. The converter is powered by the USB port on a computer or hub. For two-wire networks, the third or common wire must be used. The cable shield should not be used as the third or common wire. Connect one end of the network cable shield to earth ground. The preferred method is daisy chaining (see Figure 1). If stubs at nodes are used, the baud rate must be 9600 or less and the stub length must not exceed 60 feet. If two stubs exit a given node, the combined length of the two stubs should not exceed 60 feet. No more than two stubs should exit a given node (see Figure 1). The combined length of the network cable, including stubs, should not exceed 4000 feet. See Table 1 for recommended cables. All RS485 networks should be biased and properly terminated. See Network Cabling, Biasing, and Termination on page 2. Note: Not recommended for use with MOD I/O, 2200 PCX or TOC Analyzer. Note: Must be used with at least one device on the network that can supply biasing, such as the sc100, sc1000, Compact Analyzer or OptiQuant. Table 1 Recommended Network Cable Cable Part Number Length (ft) Page 1

2 Figure 1 Daisy Chaining PC Device 1 Device 2 Device 3 Device n Converter USB to RS485 Figure 2 PC Device 1 Device n Device 2 Device 3 Converter USB to RS485 Length 60 feet Length 60 feet Combined Length 60 feet Baud Rate 9600 Node 1 Node 2 Node n Combined Length of network cables, including stubs shall not exceed 1219 meters (4000 feet) Network Cabling, Biasing, and Termination Cabling The cable 60125xx specified in this instruction sheet, is designed for use with industrial RS485 2-wire networks. The cable provides both Data+ and Data signal connections as well as a common (return) connection. The cable drain wire(shield connection) should be connected to earth ground only at one end. Termination and Biasing All RS485 networks require biasing and termination to function properly. Biasing can be performed any place along the network path, but termination can only be added at the ends of the network path. The 60125xx cable has characteristic impedance of 120 ohms, which dictates a termination value of 120 ohms at each end of the cable for proper reflection free operation. Refer to the instrument manual to determine if the instrument network interface has built-in capability (usually via jumpers or switches) to add either biasing or termination or both to the network. If built-in capability is not available on the network, then a resistor network as shown in Figure 3 should be used to add the biasing with termination on one end of the Page 2

3 network. This network supplies proper biasing and a Thevenin impedance of 120 ohm across the Data lines. The other send of the network should be terminated with a 120 ohm resistor across the Data lines. If the USOTL4 is at one end of the network and biasing is provided elsewhere on the network, termination can be achieved by adding a 120 ohm termination resistor (R1) to the USOTL4. In this case R2 and R3 are not needed. Grounding Connect the circuit common at each node (instrument or device) along the network to an earth ground via ½-watt 100-ohm resistor. Refer to the instrument or device manual to see if provision for the 100-ohm resistor ground has been provided. It may be selectable via a jumper or switch. four 100-ohm resistors have been provided in the kit for this purpose. The 120-ohm resistors may also be sued for grounding if there are not enough 100-ohm resistors. The purpose of this resistor is to limit any potential ground loop currents. Figure 3 Terminating and Biasing Resistors Unpacking the Open the packing carton and verify that the device you have received is a B&B Electronics USOTL4 RS485 converter. The carton should contain the items listed in Table 2. Table 2 Items Included in the Kit Item Catalog Number B&B Electronics USOTL4 RS485 Converter Biasing Resistor, 300 ohm (2 total) Biasing Resistor, 150 ohm (1 total) Cable, USB CD, USOTL4 Driver Disk N/A Grounding Resistor, 100 ohm (4 total) 2602 Instruction Sheet Terminating Resistors, 120 ohm (2 total) Tubing, 1 ft 7W1048 Page 3

4 System Requirements Pentium 400 MHz or faster processor with 1 free USB port B&B Electronics Isolated USB to RS485 converter Windows 2000 or Windows XP B&B Electronics USOTL4 Setup Refer to instructions supplied with the B&B Electronics USB to RS485 converter. Changing the COM Port Number 1. From the Device Manager, select View devices by type>ports (COM & LPT). 2. Select the USB serial port and click Properties. 3. Select the Ports Settings tab and click Advanced. 4. Choose the required COM port number from the list and click OK. Note: If a converter is attached to the USB serial port when the port number is changed, it will continue to work under the new port number. Note: If a converter was attached to the USB port but was not attached when the port number was changed, it will not work when re-installed under the new port number. In this case, the converter must be removed from the system and re-installed. Note: In general, if there are devices in the system which have not been attached previously to the USB serial port, they may not work after the port has been changed. Remove the device from the system and re-install. Configuring RS485 2/4 Wire Settings There are 4 dip switches that control the converter in 2-wire or 4-wire mode. All dip switches should be OFF for 4-wire mode, and ON for 2-wire mode. The USOTL4 is configured from the factory in a 4-wire RS485 mode. Hach process instruments implement a 2-wire RS485. Change all dip switches to ON for Hach process instruments. Page 4

5 OptiQuant Instrument Family Note: Each OptiQuant Instrument must be set to a unique ModBus address. See the OptiQuant Instrument Manual for configuring this address. The OptiQuant instrument family uses 2-wire (half duplex) RS485. Table 3 lists the connections necessary to connect an OptiQuant instrument to the USOTL4. A1 A2 and B1 B2 terminals must be jumpered at each OptiQuant instrument. Table 3 Connections Between OptiQuant Instruments and the USOTL4 USOTL4 Connection OptiQuant Connection 60125xx Wire Color TDB(+) A1 A2 Orange/White TDA( ) B1 B2 White/Orange GND GND Blue/White Tie the cable shield to earth ground at one end only. Up to 31 OptiQuant Instruments can be connected to the USOTL4 by Daisy Chaining one instrument to the next. sc100 Instrument Family The sc100 instrument family uses 2-wire (half duplex) RS485. Table 4 lists the connections necessary to connect an sc100 instrument to the USOTL4. Table 4 Connections Between sc100 Instruments and the USOTL4 USOTL4 Connection sc100 Connection 60125xx Wire Color TDB(+) Terminal 1 Orange/White TDA( ) Terminal 2 White/Orange GND Terminal 5 Blue/White Tie the cable shield to earth ground only at one end. Compact Analyzer (i.e. Amtax, Phosphax) The Compact Analyzer uses 2-wire (half-duplex) RS485. Table 5 lists the connections necessary to connect the Compact Analyzer to the USOTL4. Connections are made in the low voltage terminal box, refer to the Compact Analyzer manual for more information. The Terminals 24 to 26 and Terminals 25 to 27 must be jumpered. Table 5 Connections Between Compact Analyzers and the USOTL4 USOTL4 Connection Compact Analyzer Connection 60125xx Wire Color TDB( ) White/Orange TDA(+) Orange/White GND 23 Blue/White Tie the cable shield to earth ground only at one end. Page 5

6 Using the USB to RS485 Isolated Data Converter in Heavy Industrial Locations A Heavy Industrial location is defined by the IEC as: Locations characterized by separate High or Medium Voltage transformer connection to the public network dedicated to installations, other than those used for domestic purposes, feeding manufacturing or similar plants with one or more of the following conditions: Frequent switching of heavy inductive or capacitate loads. High current loads with associated magnetic fields. Presence of Industrial, Scientific, or Medical (ISM) equipment (e.g.; welding and similar devices). The USB to RS485 Isolated Data Converter can be used in Heavy Industrial Locations with the addition of a high-quality Surge Protector to the RS422/485 data lines. The addition of a high-quality surge protector to the dc and data lines will allow the converter to comply with the requirements of IEC/EN , Level-3. (2KV Surge 2KV EFT. Per EN & -5) Figure 4 shows a Hach-recommended surge protection scheme for heavy industrial locations: Figure 4 Hach-recommended Surge Protection Scheme for Heavy Industrial Locations PC Isolated RS-232 RS-485 Converter Data Line Surge Protector Networked Sensors/Devices Note: The surge protectors will only work if connected to a solid earth ground. This system was tested with MCG Electronics DLP-20-6V2 ( (Data Line Surge Protector for RS422 datalines) and DLP-10-6V2 (Data Line Surge Protector for RS485 datalines). Page 6

7 Cable Specifications Table 6 Overall Foil/Braid Shield 22 AWG, 1.5 Pair For Industrial (PLTC/CM) EIA RS-485 Applications Cat. No xx Trade Number (Ind. Stds.) Std Length Ft. (M) AWG (strand) Type (Nom. D.C.R.) Conductors Shields Nom. O.D. Nom. Imp. ohms Velocity of Prop. Nom. Cap. Belden 3106A (UL AWM: 2919) (NEC: CM) (CEC: CM) 1000 (304.9) 5000 (1523.9) 22 (7x30) TC 14.7 ohms/m (48.2 ohms/km) Beldfoil xtc Braid Individual 2.8 ohms/m (9.2 ohms/km) in (7.67 mm) % 11 pf/ft pf/m pf/ft 1 65 pf/m 2 Description Insulation Jacket Plenum Version(s) Polyolefin PVC n/a Tinned copper, datalene insulated, twisted pairs. Overall Beldfoil aluminum-polyester shield. 22 AWG stranded tinned copper drain wire. Overall tinned copper braid shield (90% coverage) Black U.V. Resistant PVC jacket. 100% shield coverage. 30 V 80 C. 1. Capacitance between conductors. 2. Capacitance between one conductor and other conductors connected to shield. Page 7

8 FOR TECHNICAL ASSISTANCE, PRICE INFORMATION AND ORDERING: In the U.S.A. Call toll-free Outside the U.S.A. Contact the HACH office or distributor serving you. On the Worldwide Web HACH COMPANY WORLD HEADQUARTERS Telephone: (970) FAX: (970) Hach Company, All rights reserved. Printed on the U.S.A. wc/kt 06/07 3ed