Gemini GV Servo Drives with a serial number greater than 99072100143 will have Z-Channel output capabilities. This feature requires an operating system of 1.01 or greater. The Z Channel only works if the ORES and ERES commands are the same. If the ORES and ERES commands are different, then the Z channel will not be output from the drive. When ORES and ERES are the same, the Z channel will output from the drive.
If your Gemini GV is older than the 99072100143 serial number, then you can have your Gemini upgraded with the latest hardware. Please contact your local distributor to have your unit upgraded.