How do I request information from a node from the gateway?

I have a relayactuator node with 2 relays that is transmitting its initial state at the startup of the node. This is also received by the gw.
But after that I cant seem to request the current relay status from the node by sending a message from the gateway.

I tried lots of combinations, nothing worked.

I thought this would be correct:
1;2;2;1;2;0\n
1=node number
2=sensor (relay number 2)
2=request
1=ack message
2=light
0=string??

Can anyone point me in the correct location?
maybe a new API page for 1.4 would be handy

edit: also I can't find anywhere what the debug letters mean
what is s=,c=,t=,pt=,l=,st= ??