Linking two levels in a house????

I installed 1 8 way dimmer module and 2 16 way open relay modules in ground floor
Connected connected cables and programmed ok.
then fitted of level two of the house and programmed etc ok.
Client wants to be able to press the switch 1 on top level near stairs to turn lights at bottom stairs on.
then press switch one on two gang down stairs and turn off etc etc.

I tryed to place a lan cable between the two switch boards about 1 meter apart.
then programmed switch with group 21 on both switchs but it will only work on ground floor not top floor did I miss something????

 

It is not clear what you mean.

Why did you use a LAN cable? This implies an Ethernet connection. What did you connect together exactly?

 

You need to do a few things after joining the two networks.

- resolve any numbering clash in the unit numbers
- simplify the naming of the dimmer loads and relay loads
- make certain the buttons are linked to the names correctly.
- consider putting in motion sensors so that you dont even need buttons.

 

Make it one

From what you've described, it sounds like you have set up two different networks in one house?
You need to join them together to be able to program some common functionality, otherwise what's really the point of c-bus apart from an over priced switch with a LED indicator in it? So just join the pink cable from both switchboards together.
Doing a 2 way switch for a stairway is a basic necessity. Ensure the both switches are programmed to control the same load, (as you think you have done it should work), ensure the network is the same on both.

My stairway lights are controlled from 5 different c-bus key inputs (switchplates) and the touch screen. Similarly external lights are controlled form a switch at each door.