Schneider Modicon M221 Modbus Write To Coil

[BillySangster]

Hi there,
I’m in the process of using an iPad as an HMI to communicate with a Schneider Modicon M221 over ethernet.

I’m using Libmod with a Swift wrapper.

I can read bits and registers no problem. Can’t seem to write anything to the device. The response is successful according to the swift (therefore C) function, but there’s no action.

Anybody else had experience of this that could help me out here?

I can provide code snippets if that helps.

Billy.

 

[BillySangster]

Sorry, that should have read “Libmodbus”, not “Libmod”.