Not that this can't be operator error but see attached. Jim noticed a large output from the ITMX Stage2. 1000s of counts is of concern; 100s is normal. Anyway, looking at dataviewer of the fast channels, I thought this was ~8Hz; but the spectum and the DTT time series says this is 120Hz. Still looking for this peak source.
OK Robert solved my problem--The Dataviewer by default comes up at 128 hz resolution and this 120Hz peak is very large. When I go to a higher 'resolution' in dataviewer it looks correct. User beware.