Connect the azimuth and elevation motors directly to the frequency inverters. Use shielded cable only. Take care, that the shield is connected to the PE terminal of the frequency inverter and is NOT connected to the crankcase. If your ACU-ODU is equipped with a polarisation drive, the terminals are located at the rail where the other terminals are mounted at. Here it is not necessarily needed to use a shielded cable. If you nevertheless use a shielded one, take care, that the shield is connected to the PE terminal of the terminals and is NOT connected to the crankcase. Please refer to the schematics shipped together with your sat-nms ACU-ODU for more detailed informations and pin descriptions. The ACU knows two different configuration modes to control a motor driver. They are called 'DIR-START' and 'DUAL-START'. In 'DIR-START' mode, the 'FWD' signal switches the motor on/off, the 'REV' signal controls the motor direction. This is the configuration many frequency inverters use. In 'DUAL-START' mode, the 'FWD' signal switches the motor on in forward direction, 'REV' activates the motor in reverse direction. This configuration mode is convenient to control a motor with relays. At sat-nms ACU-ODU it has to be configured as DIR-START for AZ and EL and as DUAL-START for POL if you have Siemens frequency inverters installed. If your sat-nms ACU-ODU is equipped with OMRON frequency inverters, all axis have to be configured as DUAL-START.