Prior to upgrading an end station sus front end system to Gentoo linux kernel 3.0.8 I have trended the ETMX and ETMY SUS statewords looking for Timing and/or ADC errors since Jan 1st. The attached plot shows the instances of these glitches on h1susetmx (red circles) and susetmy (blue circles). Since sometimes a SUS glitch is accompanied with an IOP glitch, I have also shown h1iopsusex (red cross) and h1iopsusey (blue cross).

These glitches are normally latched on. To enable trending, for the whole time a cron job running on h1fescript0 has been clearing the stateword bits once a minute.

As can be seen, the rate of errors is not constant. At the tail end of O1 EY was glitching more than EX. During Feb and early Mar both systems glitched frequently. Since then there have been quiet and glitchy periods, lasting from several days to a week or so.

The plots show that sometimes an IOP can glitch without the sus model, in most cases it is the other way around or they both glitch.