anyone used the modbus master sample code?

Hi All

anyone used the modbus master sample code provided with
RSLogix 5k?

What is the "starting address"?
e.g. if i use function code 1 with starting address 1100
and NumberofPoints = 50, i dont see it reading from that
starting address...

why?

I used this code and it works as far as I know.

In your example you will be reading coils 01100-01149.
Make sure enable bit is ON and .AddressOffsetInMaster =0
Also use only one command, and disable the rest.
Once testing is done, you can add more.

I recomend you to use a PC based Modbus Slave simulator to test your application before connecting to another device.
I used one from www.modbustools.com