This is a desk DMX backup scenario / issue

If you want a server as a backup without DMX - then you have to record all your cues as Presets and put them in a cuelist within catalyst...

However, the easiest way is to get a backup HogIII and network the DP's so that you have redundancy

Its a bit much to expect a catalyst server to perform as a backup for another bit of equipment that may fail (ie your hogIII)...

S