In an effort to reduce the potential problems with the use of modems, this article is projected to make clear how to use and set up modems with MEDOC / MMPlus and PLC’s. This article will also detail which modem types have been tested and that Mitsubishi will advise. Systems tested utilized the PLC’s and A FX series and comprised using MMPlus and MEDOC.
Test Procedure
The systems were tested for down loading and up loading and controlling of test programs with MMPlus and DOS MEDOC. The test procedures were described as following:
1. The modems were set up with the terminal emulator of US Robotics “Quick Link Modem”.
2. The Hardware was subsequently assembled and terminal emulator of “Quick Link Modem” made use of PLC modem.
3. When the connection was recognized the terminal emulator of “Quick Link Modem” was shutdown but the connection or line was left open. This was the cause for using this terminal emulator of “Quick Link Modem”. Windows terminal emulators and other standard terminal emulators seemed to go down the connection when closed down. Hyper terminal of Windows 95 was not fully tested for this capability.
4. When the terminal emulator of “Quick Link Modem”was closed DOS MEDOC or MMPlus was initiated and the port of communications and port parameters were set to equal the chosen system e.g. internal modem was COM2.
5. Program PLC monitoring, up load, and down load was then tested.
6. When MEDOC or MM+ was completed and closed, the terminal emulator of “quick link modem” was initiated, and the line of phone was hung up.
7. It was required to initiate Medoc with the I3 parameter to disable break off driven communications with some modems i.e. the line of start up is MEDOC I3.