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Message ID: 3945     Entry time: Thu Nov 18 11:06:20 2010
Author: josephb 
Type: Update 
Category: CDS 
Subject: c1sus and ADCs 

Problem:

ADCs are timing out on c1sus when we have more than 3.

Talked with Rolf:

Alex will be back tomorrow (he took yesterday and today off), so I talked with Rolf.

He said ordering shouldn't make a difference and he's not sure why would be having a problem. However, when he loads the chassis, he tends to put all the ADCs on the same PCI bus (the back plane apparently contains multiples).  Slot 1 is its own bus, Slots 2-9 should be the same bus, and 10-17should be the same bus.

He also mentioned that when you use dmesg and see a line like "ADC TIMEOUT # ##### ######", the first number should be the ADC number, which is useful for determining which one is reporting back slow.

Plan:

Disconnect c1sus IO chassis completely, pull it out, pull out all cards, check connectors, and repopulate with Rolf's suggestions and keeping this elog in mind.

In regards to the RFM, it looks like one of the fibers had been disconnected from  the c1sus chassis RFM card (its plugged in in the middle of the chassis so its hard to see) during all the plugging in and out of the cables and cards last night.

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