CAN message from PMU to V3 CAN Switchboard

I ran out of inputs for the PMU 24 so I have a V3 switchboard along side it to give me more inputs.

I also want to use the low outputs on the board for some indicator LEDs.

The CANX file on the PMU has address 0 x 642

The Light client says inputs are on the switchboard is 0 x 643

How do I get the PMU to transmit on 0643 to turn on a L1 - L4 output ?