AC500 and Aqua Master Flow Meter Modbus RTU Communication
I'm trying to connect between PM585 AC500 cpu and aqua master flow meter over modbus rtu channel. I have already confgiured everything correctly -I hope :)- the communication is done using com2. attached picture show my program settings.
I did the communication with motorolla AC3680 plc and it works well with the indentical flow meter settings.
The com-mod-mast gides me the error code 8211 (time out error)!!
The only thing that I didn't use is the resistors 470ohm and 120ohm!! does that affect my work or not??!!
Hope you can help me.
Voted best answer
First I found in your COM2 settings is RTS Control - it must be "telegram" in order to use RS485 !
Then you have to check if the settings there (baudrate, parity, data, stop...) are the same as with your Slave 1. Are you sure the start address for reading is 5060?
Put the fixed cycle time (e.g. T#100ms and not freewheeling) for your program, where COM_MOD_MAST block is used.
Last, in my programs I always put at input of COM_MOD_MAST the variables in format, as required in the help (word, byte ...) with the corresponding INIT values (2,1,3,1000...). It is easier then for commissioning too. ADR is a must too - seems OK in your program.
Check wiring - Rx/Tx.