Control.com - Nerds in Control

I am doing on Triconex system for ESD. I am stuck around one question that what is standard for safety of commuinication networking with multiple triconex system in single plant?

It depends on what the PLCs share. PLCs may share critical "shutdown" signals, "Time" function for synchronization, Alarm/Trip information, Process feedback for any HMI based systems etc.

TCM in ver.10 provides whole lot of options on communication on multiple ports to Tristation, other Tricon PLCs, Modbus master/slaves and external hosts over ethernets.

Though no standard exists, if shutdown signal is shared between PLCs, good engineering practice is to go for "peer to peer" route which is TUV approved for SIL rated application.

Regards.

Abhijit Goswami, Haldia

A simple Watch Dog Timer would be to have each slave continiously increment (and roll over) a register that is monitored in the Host. If the Host ever detects a frozen value then it would force an alarm.