This bit activates when a registration move has been initiated by a trigger since the last "GO" command. TRIGA and TRIGB are used to trigger registration moves. Bit 28 is cleared with the next "GO" command.
1) If bit 28 is not turned on when expected, check the Registration setup.
2) Determine if the trigger input is correctly setup.
3) Use the TTRIG command to check the status of the interrupt. Check the status with the trigger off, then check to see if the status changes when the trigger is on.
4) If the trigger is correctly defined, the status changes and your Registration setup appears to be correct. Check bit 30. The defined move may not be possible with the motion parameters defined.
For further information on Registration, please see the 6K programmers guide and the RE command in the 6K series command reference.