FP5 omni off

[Dr Mossi]

Hi there,

I have the following setup:
keystep pro as central sequencer
voice 1: akai mpx16
voice 2: korg ms-10
voice 3: Behringer CAT
voice 4: Roland FP5

But the FP5 is receiving midi from all channels by default. I am trying to find out how to change this. How can I turn omni off and specify only one receiving midi channel?
I found in the manual that midi cc 124 and 125 turn omni on and off, but how does it work. How do I sent this message to the FP5?

Any help would be greatly appreciated.