5500AC2 killing Cbus network

I am currently using a 5500PC and 5500PACA on a single CBUS network. I now have a 5500AC2 that will be taking over from these 2 devices. I want to put all 3 devices on the Cbus network to be able to transfer the logic and control from the PC/PACA to the AC2. However, when I connect the AC2 into the CBUS network it shuts down the network, all units power off and there is no activity until I disconnect the AC2.

• CBUS shuts off if either PC or PACA is on the network.
• AC2 functions as expected once PC and PACA are taken off the CBUS network.
• Network consists of 24 units (including PACA and PC)
• Only burden active is on the PACA
• Network has 800 mA available with 456 mA current consumption with all 24 units connected.
• 4 units with clock
• AC2 powered by 24DC supply
• CBUS toolkit diagnostics shows no errors
• AC2 using default ID of 255

Any help appreciated.

 

could be a bad cbus cable

 

Not a bad cable, the units are sitting on my desk and I'm using pre-made CAT6 cables.

 

Measure the cbus voltage. If the units power off it is dropping too low. Are you sure you have configured the units correctly to get toolkit to report the correct current availability? Toolkit doesn't recognise powered or unpowered units. You have to tell it the correct ones.

 

CBUS Diagnostic reports voltages at around 29V on average,

 

Issue sorted, One of the patch leads I was using was a crossover. Should have known not to keep those lying around.

 

A bad cable then

 

Also, for future reference, when checking the voltage you need to do it when the system is in the failed state with a multimeter, not a working state with the diagnostic utility.