Registers and slaves
I'm using CI853 module for modbus communication with AC800 M PM866 controller. We have some 30 wireless transmitter's (to check Temperature) and signals of those are coming to receiver(Gateway)
From this gateway, modbus mapping is done and all data's are transmitted to CI853. Using registers all 30 devices are accessed. Now how many slaves do I have? Should I call 30 slaves or 1 slave(Gateway)?
What is QW, MW registers? What is the difference?
You shall look at gateway configuration manual and find out whether slaves will be transparent to CI853 or not ? Most likely, you will have to call 30 slaves.
Do remember that CI853 supports RS232, which is point to point communication and may require RS232/RS485 converter. You need to once again refer gateway manual about it.
With regard to QW & MW, there are three type of memory in a PLC - I (for physical inputs), Q (for physical outputs), M (internal markers - for internal variables). The same convention is followed in AC 800m controller. As such system allows to use both Q & M for MODBUS communication and shall matter to you.