800xa PLC connect Modbus TCP/IP
We have a 800xA (5.1.4-1 RU1) system where we have installed PLC connect(5.1.400.2).
We want to read quite a lot of data from a Modbus TCP/IP slave.
But I see at least three problem for our application:
1. Analog values are sent as integer from the slave and are multiplied by a factor to get higher accuracy.
E.g. if a pressure is 1.23bar the slave sends 123.
In the “Signal Configuration” aspect the signal can be scaled, if I set Low/high limit to 0-10 and Low/high limit in PLC to 0-1000 the signal is scaled correctly but rounded to nearest integer 123 = 1bar!
2. The Modbus slave sends bits(alarms etc.) on holding registers.
Is it possible in some way to configure the address of a “PLC_Binary” as bit in a holding register address?
Normally in Modbus masters I have used you can specify the address something like 40001:4/40001_4/40001.4… to read bit 4 in holding register 40001, but it doesn’t seems possible with PLC connect?!
3. It is not allowed to use same Modbus address in more than one object.
As the Modbus slave sends many different digital signals in same holding register, I needed to read same address in many different objects.
I hope someone can give me some good advices how to solve this.