Applies To:
  • CitectSCADA 5.50
  • CitectHMI 5.50

I have a Modbus I/O Device with address 0. But the Citect does not allow reading to it. What is wrong?  

From the Modbus driver version V2.4.4.242, the address 0 is reserved as broadcast address, so no read request can be sent to it. From the version V2.5.2.0, there is a Citect INI setting to turn off the broadcast.

The setting is down to the I/O Device level. For example, if want turn off the broadcast in iodev1, which is in the port1, then

Broadcast = 0