This particular error bit has many possible causes and suggested remedies. For more in-depth information, please refer to this Hall Troubleshooting Guide or the Gemini Hardware Installation Guide. For additional Hall state troubleshooting assistance, refer to the Gemini Hall State Checking FAQ by performing a search on the keyword "THALL."
REMEDY:
Hall State-checking can be disabled by entering the DHALL1 command. However, it is only disabled after the first successful Hall transistion and commutation is taken over by the encoder. This command is only valid with Gemini units using Operating System is Revision 1.72 or newer. For Gemini units using Operating System Revision 1.81 or newer, Hall State-checking is disabled by default.