pVPD problem (Re: recent data)

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From: Frank Geurts (geurts_at_rice.edu)
Date: Sat May 03 2003 - 13:15:42 EDT

Bill, I think that these two problems (pvpd and dma) are very likely to
be related:
if the pvpd is not functioning then it is very likely that there won't
be any signals on its ADCs (which are part of the TOFp group). We have
seen before that we get DMA errors in such case because of the way the
Q-scan mode deals with those channels. The fact that you only see strobe
events and no single scalers at all makes all this point to the pvpd ...
so i powercycled both CAMAC crates and the pVPD LV supply, restarted
tofpdaq. Geary is pretty sure that the pVPD HV was switched on this
morning ... let's see what the next rhic fill brings us ...

W.J. Llope wrote:
> (localmon_to4123046.dat)
>
> Found 0 beam events out of 31356 >>--> ratio = 0
>
> -> all strobe events.
>
> pVPD singles scalers all zero too.
>
> either:
> we lost the pVPD LV supply,
> or
> we lost both pVPD FEE boards
> or
> the shift crew neglected to power up
> the pVPD HV during the STAR power-up...
>
> geary could you check w/ the shift crew on this?
>
>
> clearly there's no way i can answer frank's question
> (re: the DMA errors) w/ only these strobe events...
> anyway, the pedestals look o.k....
>
>
>

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