Dear all,

Our one Frame-9E machine on shutdown for maintenance, all <R>, <S> & <T> are showing "No OST available" and return to "A7" state, this is repeating still now. Shall you give the meaning for OST and the reason?

Thanks

 

It's "NO <b>Q</b>ST AVAILABLE" : Queue Server Task.

Try resetting the Diagnostic Alarms on the LCC/SLCC Display from the LCC/SLCC keypad. Sometimes this alarm will clear when a Diagnostic Alarm Reset is issued from the operator interface.

I would venture that some blip occurred on the StageLink during the outage, especially if there is(are) EX2Ks on the StageLink or MODHUBs.

If the processors are all at A7, it's likely just an unacknowledged, uncleared Diagnostic Alarm. This alarm can occur when downloads are interrupted, or sometimes when the entire panel is powered down and then powered back up with the mains circuit breaker without shutting off the individual processor power supplies (which is not good practice!), or when EX2000s are cycled, or when fiber optic MODHUBs are power-cycled.

(No; I don't know what Queue Server Tasks are. I only remember the mnemonic.)

 

Thank you very much for your reply

 

I've also seen these alarms come in when performing valve calibrations and other standard functions from the HMI. I believe they are caused by the calibration page requesting information that is not available, like a bad point name.

A reset typically takes care of the problem.