Yes, you heard it right! All Super PLCs are Internet-ready - you can remotely program, monitor or control your Super PLC-controlled equipment via the Internet at any time. Your PLC can also dial up via modem to get connected to the Internet, send an email or to save data to a remote location! We have the complete software and hardware solutions to attain all the above promised features today! There are two ways of connecting the Super PLC to the PLC:
1) Via the TLServer software running on a PC - The PC must already be connected to the LAN or the internet. This cost next to nothing because the TLServer is included with the Internet TRiLOGI programming software.
2) Via the Ethernet XServer module to connect to a LAN or the Internet.
I. Programming & Monitoring
The Internet TRiLOGI normally works like any other Windows based program, which lets a user program the PLCs using a single PC connected to it via the RS232 port. However, due to its client/server-based architecture, you can also program the PLC from other computers on a corporate LAN or any computers on the Internet using a Java web browser. No additional training is required for a user to program the PLC via the Internet because they are using the same Window based software that they would already have mastered during programming in local mode.
To allow the PLCs to be accessible for remote programming and monitoring, you need a networked PC which is connected to the PLC via serial ports, and this PC must run the "TLServer" software, as shown in the following diagram:
The TLServer acts as a gateway to connect the M-series PLC to the corporate LAN or the Internet. The actual connection to the Internet is provided by the PC and this may be by means of Ethernet, T-1, DSL or cable Broadband or even dial-up connection.
When a client program such as TRiLOGI wants to read from or write to a PLC, it would send a command to the TLServer using the TCP/IP protocol transported via the Intranet, the Internet or a local host connection. The TLServer, upon receiving the command, will carry out the actual reading or writing to the PLC via the PC's RS232 or RS485 port. The data received from the PLC is then relayed back to the client program via TCP/IP protocol.
TLServer is also a Web server which serves up web pages that contain the TRiLOGI Java Applet to enable you to use any Java-enabled Web browser to access the PLC without the need to install a local copy of the TRiLOGI application software.
II. Remote PLC-to-PC Connection via Modem
A remotely located M-series PLC can be connected to a host PC via public-switch telephone network (PSTN), radio or cellular phone network. This can be accomplished by using two analog modems, one connected to the PLC’s RS232 serial port, and another modem connected to the remote host PC:
Modem1: The host PC may use any internal or external modem that can communicate at 2400 bps or faster. Connect the modem to the PC as instructed in the modem’s manual and connect the phone line to the phone jack on the back of the modem marked "WALL" or "Line".
Modem2: The modem to be attached to the PLC (modem2) must be an external modem with an RS232 connection port.
TLServer 2.0 Modem Support
The TLServer 2.0, which is part of the Internet TRiLOGI version 5.1 software suite, includes built-in support for dialing a modem. Whenever a user wants to communicate with the PLC, he/she will first use the TLServer to dial and connect to the PLC’s modem. Once the modem communication is established, the PLC becomes accessible via the Internet so long as the PC running the TLServer is connected to the Internet.
You can also easily program the PLC to automatically dial in to the TLServer in response to an event. This allows the PLC to perform a number of tasks that require the PC, such as using the File Service to save or append data to hard disk files, send email to anyone via the Internet or even synchronize its real time clock with the host PC!
A number of examples have been included in the "C:\TRiLOGI\TL5\usr\File Services and Modem" folder in TRiLOGI version 5.1 or greater. All these examples make use of a powerful yet easy to use custom function that was written entirely using the standard TBASIC commands.
For more details, please refer to the i-TRiLOGI Programmer's Reference
III. File and Email Services
The new version 2.0 of TLServer provides a number of File and Email services to the PLCs via the serial comm port. Basically a PLC can send service requests to the TLServer using "tags" (which are ASCII characters enclosed between the '<' and '>' characters) and the TLServer will perform the service requests upon receiving valid commands. The PLC can easily send the tags and ASCII data using the TBASIC PRINT #n command.
Since the PLC is the one which initiates the service request, it does not need to be linked to the TLServer all the time unless it needs to request a service from the TLServer. This makes it possible for a remote PLC to connect to the TLServer via the telephone line using a modem and perform the required file or email services, then disconnects itself from the TLServer so that other PLCs can take turns to connect to the TLServer to request for services.
The following are the currently support file and email services that the TLServer 2.0 provide for the super PLCs
1. Write data to file |
Format: <WRITE [filename]> data data data... data.... </> |
2. Append data to file
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Format: <APPEND [filename]> data data data... data.... </> |
3. Email data to recipient
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Format: <EMAIL [email address]> Sender: [sender email] Subject: [subject text] data data data... data.... </> |
| 4. Read Data from File
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Format: <READ [filename]> </> |
| 5. Read Real Time Clock From TLServer |
Format: <READ RTC[]></> |
IV. Creating Your Own Java GUI Applet
Besides using the Internet TRiLOGI software to remotely program, monitor or control the M-series super PLCs, you can also write your own Java applet to provide a Graphical User Interface (GUI) for data acquisition, remote monitoring, or controlling the PLCs via the Internet.
A Java applet can be loaded from a remote TLServer and executed in any web browser without the need to install the software on a local PC. This allows you to create a program for controlling your equipment that you can execute from any cyber-cafe or at public library using the web browser.
We have made it extremely simple for users to write their own Java applets by providing an API library to our PLC users. Our Java API class library can greatly simplify your job of logging into the PLC webserver ("TLServer") and controlling the PLC via the Internet. For example, a simple applet that is shown on the left picture below, which can continuously monitor the PLC's internal clock and the logic states of the input #1 and a push button for toggling the output #1 can be created quickly. You can click on the picture or click here to see the source code listing
V. Benefits of Internet Connectivity
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Remote monitoring, control or updating of PLC programs from anywhere using a web browser. (username and password access requirements protect the system from unauthorized access)
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EMAIL: PLC can automatically send Emails to users upon event occurrence or can be programmed to periodically send production reports, etc.
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Excel Link: Automatic linking of data from multiple PLCs located at multiple sites around the world into an Excel spreadsheet for instant computation of real time process or production data. (Require purchase of TRi-ExcelLink Software)
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