A colleague of mine asked me to support a passive (scanning) mode for Modbus (RTU/ASCII) in our D2000 communication driver. So I did this week. This way he can use e.g. Moxa NPort to eavesdrop on existing serial communication. The driver analyzes both Modbus requests (starting address & number of registers are obtained) and responses (with data).
In the future, should the existing communication be discontinued, we can simply reconfigure & rewire the Moxa, disable the "Passive mode" option and start active communication.
Do your SCADA systems also support this feature? Or do you use 3rd party devices, like some Modbus multiplexers/proxies if such a thing is needed?
In the future, should the existing communication be discontinued, we can simply reconfigure & rewire the Moxa, disable the "Passive mode" option and start active communication.
Do your SCADA systems also support this feature? Or do you use 3rd party devices, like some Modbus multiplexers/proxies if such a thing is needed?