The THALL command in the Gemini command language acts as a type of "hall state firing order" check, in which you can verify that the six distinct hall states of the motor are being triggered - and in the correct order.
VERY IMPORTANT: ***READ THE ENTIRE PROCEDURE BELOW BEFORE ATTEMPTING TO PERFORM THIS TEST!!***
To verify that your motor's hall effect sensors are operating properly, perform the following procedures:
1) Connect your RS232 cable into the Gemini product that you are using, open up Motion Planner on your computer, and select the corresponding Gemini drive from SETTINGS in the COMMUNICATIONS pulldown menu. Then go to the Terminal screen and verify communications with the Gemini unit.
2) VERIFYING ALL HALL STATES ARE FUNCTIONAL: Type THALL. You should get a response back (example: *THALL6). Now, hand-turn the shaft a very small amount in the CW direction. Type in THALL again. If the THALL value has not changed, turn the shaft a very small amount again, and once again type THALL. When THALL returns a different number, you have triggered a new hall state. Continue rotating the shaft and checking THALL in this manner; you should eventually see all six hall states as you continue to manually rotate the motor shaft. This will verify that all the hall sensor states are triggering. If you do not see all six hall states over the span of one motor revolution - or the THALL value never changes at all - one or more of the motor's hall states is probably bad. Check your hall sensor wire connections, and repeat the test procedure to be sure.
3) VERIFYING THE CORRECT HALL SEQUENCE: As you turn the shaft as described above, you should get the hall numbers in this order:
[1, 5, 4, 6, 2, 3, 1, ...]
THIS IS THE CORRECT HALL STATE ORDER! If the hall states do not follow this precise pattern, then the hall sensor wires (or the motor wires) are wired incorrectly. Check the wire connection assignments for your particular motor. Or, you may have to alternate the motor wire connections at the Gemini to acheive the correct order. This may require randomly rotating the wire conections. If the halls trigger correctly sometimes and incorrectly other times, check all motor wires to make sure that there are solid connections to prevent any intermittent Hall sensor faults.
NOTE FOR TESTING OTHER MOTORS: There will be n-times 6 hall states over one revolution of the motor (where n equals the number of pole pairs of the motor).