On-Line Monitoring

From within the TRiLOGI software, you are able to read/change the physical logic states of all the I/Os and internal variables of the target PLC, by using its excellent "on-line monitoring" capability. On-Line Monitoring uses the same I/O and variables display screens as the simulator to display the real-time data it captures from the PLC. Hence the experience of using on-line monitoring is nearly identical to that of using the simulator.

Note: In order to perform on-line monitoring, the TLServer must be actively running. TLServer can be running on the same computer that TRiLOGI is running at (using localhost IP 127.0.0.1), or on another computer on the same local area network, or at anywhere in the world with an Internet connection. The experience is identical regardless of where the TLServer (and hence the PLC) is situated.

Activating On-Line Monitoring

You can activate the on-line monitoring mode by cicking on the "On-Line Monitoring" item under the "Controller Menu" or simply press <Ctrl-M> on the keyboard. A password dialog will appear for your to enter the Username/Password pair to for authentication before you are allowed to gain access to control the PLC. The Username/Passwoard must have already been defined in TLServer  before you can use them.

ID (Hex)

Since a TLServer can be connected to as many as 256 M-series PLCs, each PLC must have a unique ID for identification. You will need to enter the matching PLC's ID here for successful communication with the PLC. The number entered should be in hexadecimal, hence the range of acceptable numbers is from 00 to FF.

If there is ONLY ONE PLC attached to TLServer and you are not sure of its ID, you can ask TRiLOGI to detect its ID by clicking on the "Detect ID" button.  This method however will not work if there are more than one PLC being connected to the TLServer since all connected PLCs will attempt to send their IDs simultaneously and therefore TLServer will receive garbled data.

Username & Password

You must have a username and password defined in TLServer and the same username/password pair must be correctly entered here for authentication.

Memorize Username & Password

When you run TRiLOGI Version 5.1 as an application you will have the option of memorizing the username and password so that you don't have to enter them every time. If the checkbox is left unchecked then the username and password will not be saved when the program quits.

TLServer's IP Address: Port

• If you run the TL5 as a local application on your PC, you will need to enter the TLServer's IP Address: Port. However, when running the TL5 as an applet off your Internet browser, this field is not editable and it will automatically be filled with the IP Address of the TLServer from which the applet was loaded. This is because the Java Security model dictates that a Java applet can only communicate with the server from which it was loaded (also known as "applet can only phone home!") . Hence for applet, you will not be allowed to switch to another TLServer of a different IP address.

• Therefore, if TL5 is run as an application it is very powerful because it is able to program/control/monitor any  M-series PLCs in any part of the world. All you need is just an IP Address and the Port number of the TLServer as well as the authorized username and password to gain access to the PLC. If you leave this field blank, TRiLOGI will automatically fill it with the default local host address: 127.0.0.1:9080.

Use HTTP Proxy Server

1. Unchecked: 
   
   If this field is unchecked, then TRiLOGI will communicate with the TLServer by opening a direct TCP/IP socket connection. This is the fastest and most efficient method of performing on-line monitoring since an opened socket is available for communication all the time until you abort it by closing the connection or exiting the program. This should be the default option you should try first. If the TLServer is running within the same Local Area Network as your TRiLOGI program, this normally should not be a problem.   Alternatively, if both TLServer and TRiLOGI are running on computers that can establish direct connection to the Internet (such as via dialup, DSL or cable modem), this should work well too.

2. Checked:
   
   However, if TLServer is connected to the Internet and has a direct IP address, but you are accessing the Internet behind a corporate firewall, the situation will be more complex. Due to security concerns, the corporate firewall normally does not permit the software on its LAN to establish direct access to the Internet. Although you may still be able use your browser to visit Yahoo! to check your stock prices, this is normally done through a "Http proxy server"  provided by your network administrator. The proxy server is the only program that has the right to access the public Internet.  That is to say, your browser actually makes a local connection to the proxy server, and the proxy server in turn connects to the public Internet to obtain the requested data  (hence the name "proxy") and passes the information back to your application.

If your situation is what we described above, you have three choices to communicate with TLServer:

• Ask your network adminstrator to grant you and/or your workstation the permission to make direct connection to the Internet via a special port number. Then configure TLServer to use the same port number. This situation will be most ideal since you can use the efficient direct TCP/IP connection to communicate with the TLServer.

• If the above is not possible due to your company's policy, then you can click on the "Use HTTP Proxy Server" checkbox to select it. TRiLOGI will then "tunnel" through the firewall by using the HTTP protocol to tranport the command/response messages via the network's HTTP proxy server. This technique is a workable, albeit a slower means of communicating with the PLC. (If the Internet traffic is light, you may not even feel much difference from using the direct socket connection).

• You may establish a direct link to the Internet via a separate dial-up connection from your PC. However, please make sure that you check with your company's network adminstrator first to determine whether you are allowed to do so. This will help you avoid getting into trouble for breaching the company's security policy.

TRiLOGI Application vs Applet

If TRiLOGI is running as an "Application" on local PC, then you will be prompted to enter the HTTP Proxy Server IP Address and Port number  (e.g. 165.23.345.1:8080) . You can ask your network adminstrator for the proxy server's address or check it out from your Netscape or IE5's option menu.

However, if you run TRiLOGI as an applet using the browser, then you will not be prompted to entser the HTTP proxy's IP Address. This is because the TRiLOGI applet makes use of the browser itself to perform the HTTP tunnelling.  Due to Java Security model, Applet will not be able to connect to the client's network proxy server directly. It can only use the browser's built-in proxy settings to do the job. (The browser's built-in proxy settings must have been correct to access TLServer via proxy server, otherwise you would not have been able to run TRiLOGI as an applet from that TLServer in the first place!).

 

After you have successfully log-in to the TLServer, a "Full-Screen Monitoring" window will be opened for you to monitor and control your PLC. At the same time, a red color banner will be displayed along the upper status line of the  ladder logic screen to warn you that it is performing monitoring function. The I/O logic states of the target PLC will be updated on both the ladder diagram as well as the Full Screen Monitoring window periodically. For descriptions on Full Screen Monitoring window please click on the following link:

 Continue to Full-Screen Monitoring