Remote alarm indication


Thread Starter


Hello folks.

Would like some ideas on this 'little' problem I have. Or rather a problem my boss has but has delegated me, nice!

I have a PC based CITECT SCADA system in an engineering plant room office. When certain alarms are generated by the SCADA system I need to give audio and visual alarms in a security gatehouse that is some 400 metres from the PC.

Unfortunately our customer informs us that the cable duct between the engineering office and gatehouse collapsed some years ago and so is not available!

The only thing I can think of at present is to dial-out via a modem when an alarm is generated. However I have no experience with what to connect the other end?

I have thought about using a small 'mini' PLC with a built in serial interface, and triggering digital lamps and sounders in an alarm panel.

Would a smallish HMI do the same thing. The visual
bit is OK, but do any HMI's have buzzers, sounders?

I think in Citect SCADA you can go for the RS 485 MODBUS protocol, i think it supports what you have to do is just go for line driver at receiver end and use the serial port of the citect scada. Or otherwise use optical fibre port


Devang SHah

Con Alexandrovsky, Electical Eng., Jeld-

Use the "AlarmActive(1)" function in the Trigger field of Events to activate an audible alarm from a PLC output. You will need to create a new Events record using "AlarmActive(1)=0" to turn the alarm off.