BRX PLC connecting to a ATV630 via Modbus TCP

[meridianelect]

Having trouble reading Modbus address 403202 (motor frequency ).I have tried other addresses but all I get a reception code 2 .the only one I have managed to get to work is 400001 without a error and that is not even a valid address .

[Bastian_Schmitz]

Which Unit ID did you use? If you use 255 you talk only to the IO Scanner which are defined in the VSD. If you want to read random parameter you need to use a differen Unit Id between 1...247 which is definded as Modbus RTU Address in the VSD. (don´t forget to resart the VSD after configuration of the Modbus RTU address)

[meridianelect]

I was using unit ID 255 ,as that is the default and recommended setting in the BRX.IF I change it to unit 0 (I have another Brand ,a CLICK PLC working just great on unit #0)than It still gives me a error but exception code is now 1.what causes this code ?any ideas?

[LeTomas]

HI @meridianelect ,

The ATV6xx has a "Drive I/O Profile" table where you can configure which information you can read/write from/to the drive.

In order to access to that information you will need to look at the address 0 (check in your system if you need to add 1 or not), take a look in the configuration in one of our software with the ATv6xx via ModbusTcp IOscanner:

I hope this can help you.

Best regards,

LeTomas

[Bastian_Schmitz]

If you use Unit Id 0 you will send a broadcast message were you donot get an respones. This could be the reason why you get shown a error. If you wan´t directly read/write the parameters you need to activate a modbus RTU address and use the dedicated Unit id. Or you need to configure the IO Scanner like from LeTomas described.

[meridianelect]

I have it working now ,The unit ID was the Issue .IN somove software under the "MY Device" tab in the structure box it will tell you Info on the Modbus Slave. the Id you use is 248 .All my Schneider drives have that as there Id number ,not sure if that changes on newer models but it worked for my application .