Technology Spotlight on Cellular Data Networking for SCADA system networks. Presented by Teamwork Solutions, Inc.

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1 on Cellular Data Networking for SCADA system networks Presented by Teamwork Solutions, Inc.

2 Wireless (Cellular) Data Networking Internet SCADA Server

3 How Wireless (Cellular) Data Networking Works Dynamic IP Service Plan The wireless router finds a cellular tower, just like a smart phone or tablet PC, and is given a dynamic IP address on the service provider's network. This gives the router, and any devices attached to its local area network internet access. Applications may be written that allow devices from the remote site to write data back to servers visible via the Internet. Internet SCADA Server

4 How Wireless (Cellular) Data Networking Works Static IP Service Plan The wireless router finds a cellular tower, as in the previous example, but now is given a static IP address on the service provider's network. This means that the router has a permanent address on the Internet. Now the router and its attached devices may be communicated to via that Internet address by SCADA servers. Internet SCADA Server

5 Wireless Router Settings Wireless routers have settings very similar to those one might find at home, except there is cellular signal strength and provider information, in addition to the WAN (Wide Area Network) and LAN (Local Area Network) settings. Below is an example of a Wireless Router's Status Overview: LAN IP Address WAN Static IP Address Cellular Signal Strength

6 Wireless Router Settings A common method for allowing connections to multiple devices at a remote site through a wireless router is to use port forwarding. This allows a user to specify that incoming requests on a certain port, like port 80 (used by web browsers for html content), will be sent to a certain IP address on the LAN side of the router. Below is an example:

7 How to configure a SCADA system to make requests to a controller attached to a cellular router at remote site: Internet SCADA Server SCADA Server is connected to the Internet The SCADA software is configured to Poll Modbus TCP devices on port 502, and uses IP address to connect to remote RTU. WAN IP: LAN IP: Port Forwarding set to send requests on port 502 to IP LAN IP: RTU Talks Modbus TCP on Pot 502

8 Recommended Products Reliable, flexible, and high performance SCADA software for any industrial automation moniotring and control application. Sixnet Industrial Wireless Routers Wireless routers with Ethernet and Serial connectors built for harsh industrial environments. Sixnet Ethernet based I/O and RTUs

9 on Cellular Data Networking for SCADA system networks Presented by Teamwork Solutions, Inc.

10 Wireless (Cellular) Data Networking Internet SCADA Server This brief presentation outlines how cellular routers and modems may be used to help extend a SCADA network. Cellular routers and modem offer a fast, reliable, and cost effective way to make connections to parts of your operation previously unavailable for automated monitoring, or to replace expensive and outdated communications methods like leased telephone line connections.

11 How Wireless (Cellular) Data Networking Works Dynamic IP Service Plan The wireless router finds a cellular tower, just like a smart phone or tablet PC, and is given a dynamic IP address on the service provider's network. This gives the router, and any devices attached to its local area network internet access. Applications may be written that allow devices from the remote site to write data back to servers visible via the Internet. Internet SCADA Server Using cellular routers and modems with a Dynamic IP address data plan. Devices like smart phones and air cards are typically paired with data plans that use dynamic IP addressing. This means that the devices are given an IP address by the carrier each time they register on the network. This type of data plan can be used with an industrial cellular router as a part of a SCADA network, given the proper application requirements. A good example of such and application is this: You have an RTU at a remote site that collects data locally and then at a predetermined interval (perhaps once a week) uploads its data to a PC at a central location. Because the remote RTU uses the cellular router to get out to the world and initiates communications a dynamic IP is fine. In this case the central PC does not need to know the address of the remote system. The central PC, however, does need to have its own static IP so that the remote RTU can find it.

12 How Wireless (Cellular) Data Networking Works Static IP Service Plan The wireless router finds a cellular tower, as in the previous example, but now is given a static IP address on the service provider's network. This means that the router has a permanent address on the Internet. Now the router and its attached devices may be communicated to via that Internet address by SCADA servers. Internet SCADA Server Applications where the remote site is queried or polled by a SCADA system require a data plan with a Static IP. In this case the cellular router or modem would be give a permanent address by the cellular service provider, and this address will be available via the Internet. Because the cellular router has a permanent IP address is can easily be located by the central SCADA system and is always available for polling. Because of this it can be treated much the same as a local data source by the SCADA system. In order to limit unnecessary data usage it may be desirable to poll these devices at a lower rate than local devices, but they will be available anytime you wish to reach them. This also means you can easily connect to PC's and controllers at this remote site to make programming changes, or troubleshoot their operation.

13 Wireless Router Settings Wireless routers have settings very similar to those one might find at home, except there is cellular signal strength and provider information, in addition to the WAN (Wide Area Network) and LAN (Local Area Network) settings. Below is an example of a Wireless Router's Status Overview: LAN IP Address WAN Static IP Address Cellular Signal Strength Cellular Routers and Modems are configurable devices much like the routers and firewalls used in conjunction with DSL, Cable, or other hardline Internet connections. The main status page of these devices usually displays the information common to their hardwired cousins, like LAN address, WAN address, etc., as well as cellular specific information like carrier and signal strength. To configure the device for SCADA networking you typically have to do a little setup work regarding the LAN settings, Port Forwarding, and DMZ settings.

14 Wireless Router Settings A common method for allowing connections to multiple devices at a remote site through a wireless router is to use port forwarding. This allows a user to specify that incoming requests on a certain port, like port 80 (used by web browsers for html content), will be sent to a certain IP address on the LAN side of the router. Below is an example: For many SCADA applications you will need to enable port forwarding and configure where messages on different ports are routed. For example if you have a Modbus TCP enabled RTU at IP , and a PC housing a web server at IP both connected to your cellular router your routing rules might look like this: Port 502 to IP Port 80 to IP In this fashion you are allowing for Modbus TCP messages, which use port 502 by default, to be forwarded from the router to the RTU. And http messages, which use port 80 by default, to be passed to the web server on the PC at This level of configuration is typically easy to complete, and intuitive in most configuration environments.

15 How to configure a SCADA system to make requests to a controller attached to a cellular router at remote site: Internet SCADA Server SCADA Server is connected to the Internet The SCADA software is configured to Poll Modbus TCP devices on port 502, and uses IP address to connect to remote RTU. WAN IP: LAN IP: Port Forwarding set to send requests on port 502 to IP LAN IP: RTU Talks Modbus TCP on Pot 502 The diagram above shows the communications to the RTU using the routing scheme outlined on the previous page. When using port forwarding on your cellular router your SCADA system will use the router's WAN IP address (the static IP address assigned by the cellular carrier) as if it were the RTU's address. The router then uses the port forwarding rules to forward the messages onto to the proper device on its local network.

16 Recommended Products Reliable, flexible, and high performance SCADA software for any industrial automation moniotring and control application. Sixnet Industrial Wireless Routers Wireless routers with Ethernet and Serial connectors built for harsh industrial environments. Sixnet Ethernet based I/O and RTUs The products listed above are products that I have personal experience with, and can be configured to work together to create a SCADA system that delivers highly reliable communications via a cellular network link. Please feel to questions regarding SCADA communications, or cellular networking to me at eric@teamworksolutionsinc.com