Saturn_Europa
Member
My employer has remote sites that that have recently been upgraded from relay control to plc control with a cell modem. The Wonderware DA Server picks upm right from the the plc at the remote site using cell modem conductivity. There is scripting and a "hand shake" that takes place on the wonderware side, if it sees a communication loss it triggers a comm loss alarm and a plc fault alarm. Wonderware has no way of telling if the cell modem is the problem or the PLC. Win911 has been blowing up the oncall phone because the alarm will come in and be acknowledged then the modem will pick back up after an hour and the alarm will return to false. Then the modem loose connection for 5 minutes and the alarm will go to true triggering another alarm.
These sites havent had SCADA for 30 years and have back up dialers so the com loss is a non issue and can be addressed the next day. The PLC fault needs to be addressed in a timely manner though. Thus the need to separate these two alarms.
Whats the best practice for a PLC fault alarm. We have AB Compact Logix. RS Logix 20.04. Should be as simple as wiring in a Digital Output to always be a 1 right to the back up dialer? Whats the best practice for wiring up a PLC fault to dialer?
These sites havent had SCADA for 30 years and have back up dialers so the com loss is a non issue and can be addressed the next day. The PLC fault needs to be addressed in a timely manner though. Thus the need to separate these two alarms.
Whats the best practice for a PLC fault alarm. We have AB Compact Logix. RS Logix 20.04. Should be as simple as wiring in a Digital Output to always be a 1 right to the back up dialer? Whats the best practice for wiring up a PLC fault to dialer?
