Applies To:
  • CitectSCADA 1.00, 1.01, 1.10, 1.11, 1.20, 2.00, 2.01, 3.00

Summary:
Question: I am using CiNet and Citect keeps polling the modem stopping any remote clients from logging in. I have setup the -h option correctly, however Citect still keeps polling the modem. What is causing this problem? 

Solution:
When you use the -h option it is telling Citect to not transmit out the serial port unless DCD is set. You must also setup your modem so that it controls the state of DCD. The modem should set DCD to indicate the state of the carrier signal between the two modems. Your modem may default to setting the DCD in the ON condition disregarding the state of the carrier from the remote modem. In this case Citect will keep polling the modem with the -h option. Check your modem documentation for details on how to enable this option.

You should also check your cable to make sure that the DCD is wired correctly between the modem and the serial port. If you have a serial cable test device you should check the state of DCD and make sure it is only ON when a remote modem has attached.

 

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