Error messages from EPICS Device Support Code

This assume that you have 3.26a firmware on your CAEN SY527
On this release it is known that there's a bug when we use SY527
from CAEN V288 via H.S.CAENET.

This bug of firmware causes "random periods of no CAENET response
from the SY527 system".
By this effect you may have error messages from EPICS device support code like

"CAENET Module does not exist when send command add channel=* group=* crate=*",
"CAENET Channel or Board not present when send command add channel=*,,,"
or
"Unknown Error Number when send command add channel,,,".
and
"Update Status Cache error"
"Update Param Cache error"

The results of those error is that the cache information for each HV channels
are not created properly during iocInit(initilization of IOC).
We know that you have chance to make it created properly if you just repeat
last setup of channels like total # of HV channels or group ID for each HV
channels.
But if you change something above error may happen



Reason why error occurs

From our experience it is thought that the error caused by bug of SY527 system
may happen 'cause there are some conflicts between the infomation on ROM on
SY527 and the configuration file(HV.hvc) which define the channel assignment on SY527 and cache information on IOC.
In most case "Add channel to Group CAENET Command"(0x50) fails if we modify
group ID of that channel.
Here you can see the flow chart of CAENET Command during "iocInit".

How to solve/avoid error

The easiest way to avoid error discribed last chapter is to upgrade the
firmware to 3.26d or higher but there are some other solution besides that.


1)Repeat the failed commmand for 10 to 20 times every 500msec

We have not tried this but this can surely helps you
If you see errors after tried this you may have more serious problem
that we cannot help


2)Modify the position of each board(A938AN)

This causes the ROM on SY527 which keeps last information about channels
being cleared.
And of course there's no conflict between information on SY527 and HV.hvc.

3)Format ROM on SY527

We don't say this is a good way to solve error but keep this in mind
for emergency.


TOF Online Monitor/Control Person

Kunio Koseki, Univ. of Tsukuba
Last modified: 12 May 1999