Can anybody tell me a model or make of a modem that takes serial RS-232 input and modulates it for audio signals to be sent over radios? Actually we have a revamp job in which the existing Emerson RTUs are to be replaced with Siemens RTUs.

The OLD RTUs had a built-in modem for radio communication which took serial connection at input and a PTT enabled output, i.e. the output has Rx, Tx, PTT+, PTT- and COM.

The new RTUs of Siemens only have a serial output (from TIM). Siemens do not have a product to support modulation for radio communication. Can anyone please recommend me a modem that can be used in this scenario after the TIM?

 

Try this site:

http://www.calamp.com/calamp_3_monitorcontent/monitoring_control.html

 

With radio communication work Moscad and ACE from Motorola (http://www.moscad.com). We work with Moscad over radio many year and It's really work.