PC & PLC Hardware Setup and Configuration.


A.    PLC Connected to The Ethernet Switch

If your Ethernet equipped PLC (Nano-10, FMD and F-series PLCs) is connected to the same local area network as your PC, then it is very simple to access the PLC as you only need its IP address to login and program/monitor the PLC. You do not need to run the TLServer or connect the PLC to the PC's serial port.

B.    Single PLC to One PC Running TLServer

To program the PLC without connecting it to the Ethernet, the simplest configuration will be when there is only one PLC and one PC involved. You simply connect the PLC serial port (RS232 or RS485) to the any of the  PC's matching serial port and run the TLServer.  When you are using TLServer for the first time, you may have to configure TLServer's serial port  to match the communication port number.

Note: Most newer PCs today may not come with any RS232 or RS485 port but they will usually have a few USB ports. You will need to purchase a USB-to-RS232 or USB-to-RS485 (e.g. the U-485) converter in order to connect to the PLC's RS232 or RS485 port.

C.     Multiple PLCs to One PC Running TLServer

You can connect multiple F-Series, Nano-10, FMD or M-series Super PLCs to a single PC running TLServer by connecting every PLC's RS485 in a daisy-chain manner to the PC's RS232 port. You do need to purchase an USB to RS485 converter (e.g. the U-485) to connect the PC's USB port to the RS485 network. Please refer to the PLC's User Manual for details on installation issues regarding electrical specifications and termination requirements when connecting the PLCs in an RS485 network.

i-TRiLOGI can log-in to the TLServer and have immediate access to all the PLCs on the RS485 network just by specifying the ID address of the PLC concerned. Up to 255 Standard M-series/F-Series PLCs can be networked to a TLServer for programming and monitoring!

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D.     Networking Consideration

The networking method used by the PC running the TLServer, as well as how the i-TRiLOGI client software accesses the TLServer will have impact on the configuration of both the TLServer and the i-TRiLOGI client. We will consider various scenarios below.

  1. Standalone PC (No network connection)

If the PC that runs TLServer is a standalone without any network connection, you can still use it for localhost programming. i.e. The PC which is running the TLServer will be the same one that is used to run the i-TRiLOGI client program.

When you run TLServer you will see that the displayed IP Address is the "localhost" address: 127.0.0.1:9080   (assuming that you did not change the default port = 9080). You can either run the i-TRiLOGI Application directly or you can open up your web-browser and key in the following URL:  http://127.0.0.1:9080 . In the latter case, you are running i-TRiLOGI as an applet that is loaded from the TLServer.

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  1. TLServer has Direct Connection to the Internet

If the PC running the TLServer enjoys a direct connection to the Internet via dial-up, DSL, T1 line  or cable modem, then TLServer will be accessible to any client on the Internet.

  1. TLServer is on a Local Area Network

If the TLServer is running on a workstation that is part of a local area network, it is unlikely that the workstation will have a direct connection to the Internet (unless the System Adminstrator has deliberately configured it for that purpose). When the TLServer starts, it will report the IP Address of the workstation which is the Intranet IP address and NOT the Internet IP Address.

Now if the i-TRiLOGI client is  running on another workstation which is also part of the same local area network, then it is quite simple: TLServer can be assigned any unused port number above 1024 and the i-TRiLOGI client can access TLServer from any other workstations. However, avoid setting TLServer to port 80 since by default, port 80 is reserved to serve up HTTP web pages.  Also you may need to configure the Windows Firewall on the PC running the TLServer to open the TLServer port (default is 9080) for access by other client on the network.

  1. How to access TLServer running on a Private LAN from the Public Internet?

If the workstation that TLServer is running on does not have a direct Internet connection to the Internet, then it will normally not be possible to access the TLServer via the public Internet since the LAN's  firewall will block any attempts to access a PC inside the LAN. There are two possible ways to overcome this:

  1. Consult your System Adminstrator to configure a Network Address Translator that will assign you a public IP Address which will be mapped to the local workstation that runs the TLServer. If there is a business need for your PLCs to be constantly accessible from the Internet, the System Adminstrator should be able to grant you that permission.
  2. If you are using a small home office router (such as Linksys, NetGear etc), you can usually configure these type of routers to "Port Forward" the port number of TLServer (such as 9080) to the PC running the TLServer. Once configured, all internet TCP/IP messages targetting port number 9080 will be automatically forwarded to the predefined PC that runs the TLServer program and you therefore can access the PLC via the public Internet.
  3. If your  need to provide connectivity from the Internet is only temporary (e.g. allowing your contractor to fix a software bug) it may be easier to use a 3G modem and connect the PC's Ethernet port to the 3G modem to connect to the Internet. Once the connection is no longer needed, just disconnect the modem. However, before you do this, please check with your company's System Adminstrator to make sure that you are not violating the security policy. If that is a problem, you may consider using a standalone notebook computer or PC (i.e. not connected to the LAN) to make the dial-up connection, which provides temporary Internet connectivity for the TLServer (and hence the PLCs) but will not compromise the security of your corporate Intranet.