This error is the result of an open thermal switch circuit between the motor and the Gemini drive.
When the motor's internal thermal switch gets to a certain temperature, typically around 125 degrees C, it opens thereby telling the drive that it is hot. The case temperature of the motor becoming extremely hot often accompanies this condition.
This can also be attributed to a broken, loose, disconnected or missing thermal switch wire between the drive and motor.
1) Check the thermal wire connections between the drive
and motor to insure that they are securely connected. If all connections are secure, disconnect the feedback cable from the Gemini and measure the resistance between
the two thermal wires in the cable with an ohmmeter. If a large resistance is measured, the thermal switch is bad, and the motor will need to be sent in for repair. A good temperature switch will measure much less than 1 ohm.
2) If using Gemini Operating System 1.83 or newer, the DTHERM1 command can be used to disable thermal switch-checking altogether. (NOTE: The DTHERM1 command is REQUIRED when using BE16 motors with the Gemini, as these motors have no thermal switch.)
3) Make sure that you are using the correct cables between the Gemini and motor. Also make sure the motor's connection-type is compatible with the cables and Gemini. For example, the difference between the SM motors with the -MS and -GS type connections is that the thermal wires were moved from the motor cable in the -MS to the feedback cable in the -GS. Other than that change, the cables are the same. Therefore, a Gemini using the SM's GS CABLE kits with an SM motor that has the -MS connections will cause the thermal switch to be seen as open.