# Please make the STOP command more reliable in the hexapod

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#### Details

• Type: Story
• Status: To Do
• Resolution: Unresolved
• Fix Version/s: None
• Component/s:
• Labels:
• Team:
Telescope and Site
• Urgent?:
No

#### Description

Based on recent MTHexapod testing it appears that the STOP command is sometimes ignored. The CSC runs the following command sequence:

 Set position:  codcode=enums.CommandCode.POSITION_SET  params1-6=desired position   Move point to point:  code=enums.CommandCode.SET_ENABLED_SUBSTATE  param1=enums.SetEnabledSubstateParam.MOVE_POINT_TO_POINT  param2=sync   Pause for a short time (as little as 0 seconds)   Stop:  code=enums.CommandCode.SET_ENABLED_SUBSTATE  param1=enums.SetEnabledSubstateParam.STOP 

If the pause is too short the stop command is ignored and the move finishes normally.

I consider this a serious, high priority bug that requires a lot of tricky code to work around in the CSC – code that delays sending the STOP command.

Please also check if the rotator has the same problem. If it does then please file a ticket or ask me to do so.

#### Activity

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Te-Wei Tsai added a comment -

I think the low-level controller code will need some time to write the new received command to the cmdMsgBuffer as a thread-safe circular buffer now after the update of DM-28687 (the mutex lock is used). Therefore, it might be better to let the CSC add a small time between the commands.

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Te-Wei Tsai added a comment - I think the low-level controller code will need some time to write the new received command to the cmdMsgBuffer as a thread-safe circular buffer now after the update of DM-28687 (the mutex lock is used). Therefore, it might be better to let the CSC add a small time between the commands.

#### People

Assignee:
Te-Wei Tsai
Reporter:
Russell Owen
Watchers:
Russell Owen, Te-Wei Tsai