Signals on ports can be made via inputs 1-4 and manual via the green pushbuttons 1-4. Below every green pushbutton is a small red button to open the inputs. Check that the input ports are open.
If the 540 does not recognise a manual signal via green button, the firmware needs to be updated.
If the port is open, but the port still does not recognise the signal, send the 540 back to your supplier.
Firmware update: Download firmware updater
firmware from TAG.
Connect the 540 via RS-232 / USB to the computer. Identify correct COM port.
Start Firmware updater, select the firmware, power on the 540.
Wait for the update to complete.