Command and Mechanism errors

Command accepted mechanism active ( error code C0)

This is not an error, and indicates a that a command has been accepted, is being action and that the mechanism is moving, this value may be or'd with other command errors.

Command accepted, task active ( error code 80 )

This is not an error, and indicates a that a command has been accepted and is being action, this value may be or'd with other command errors.

01 - Mechanism is busy

If a command had already been accepted and another was sent for the same mechanism then a mechanism error 01 is given, allow the previous command to complete before sending another, the active command is not affected.

02 - Command rejected - Out of range

A parameter sent was out of range, each mechanism has an operational range which has been exceeded, no action is taken.

03 - Command rejected - Invalid parameter

To many or too few parameters were given, no action is taken.

04 - Command rejected - Invalid format

05 - Command rejected - Monitor mode list full

The list of monitors which will receive status commands is full, usually this is only the system computer, reset the 4MS if necessary to ensure that no monitors a left on the list inadvertently.

06 - Command rejected - Invalid function

Each mechanism has valid functions, e.g. a move command cannot be issued to the DOR mechanism, if the function is not allowed then this error is given and no action is taken.

07 - Filter wheel is interlocked - access cover open

The MFW cannot be moved because the access cover is open,

08 - Command has been cancelled

The network cancel command was used on the mechanism.

09 - Node-name not entered on Monitor mode list

Mechanism errors

Use the engineering terminal to identify the mechanism error given for the mechanism. This is the EEmech field half way down  the display (see the section on the engineering terminal ). Alternatively, use the error message given by the mimic display.  The section on the VAX/Mimic display lists the error messages against the mechanism error number.

The following pages list the mechanism errors. Each error is listed in numerical order on at least a single page. A description of what the error is indicating is given and probable causes and possible corrective actions are listed. Space is left for other findings to be included against each error code, it is therefore important to use the copy of this document kept in the WHT control room, as the fault may have been seen before, if you do make any findings during fault diagnosis that you consider may be of value, please included them in the space provided for future reference, please include extra pages if necessary.

Quick reference listing:

01   Mechanism time-out

02   Serial link time-out

03   Serial link access time-out

04   Only ADC control and status commands are enabled

05   No encoder position change detected

06   Did not achieve requested position with required accuracy

07   Maximum mechanism move attempts exceeded

08   Datum switch not located

09   Shutter status fault

0A   Mechanism at limit switch

0B   Linear encoder module error

0C   Detent status error

0D   Encoder calibration at datum exceeds limit

0E   Failed to find limit switch during datum set

0F   A to D module failure

15   Time-out on barcode read

16   Bar code read failed after repeated attempts

17   SMDC axis and SMCM channel access time-out

18   SMCM channel access time-out

19   Motor drive card error

1A   SMCM parity error

1B   No acknowledgement from SMCM

1C   Wrong PFIP LIMPIT channel number from SMCM

1D   No PFIP LIMPIT channel active

1E   Unrecognised command sent to SMDC

1F   Unrecognised reply from SMCM

20   Encoder near limit

21   Comms link unreliable - succeeded after multiple attempts

22   Barcode read required many attempts

23   Unencoded mechanism - position unknown

24   Relative Humidity limit exceeded

25   Mechanism has been stopped by a STOP command

26   Main Filter Wheel interlock: Cover not in place/cables disconnected