I just installe a new Switch Actuator from HomeMatic (HM-LC-Sw4-WM).
I saw that in the device setup, I can choose different functions for the actuators. Like to be just a ON or a OFF switch and also the possibility to make ON or OFF impulse for the desired time.
So I thought that could set up one channel to be a Button, and this what i did, in order to command my light Pulse Relais (ON/OFF).
But I cannot make it work via Openhab, no matter what are the Homematic parameters.
So your item needs to be: Switch Relais4 "Lights" <switch> { homematic="address=MEQ04XXXXX, channel=4, parameter=STATE" }
You have a wrong syntax for the iconname. That could be the problem in your case.