Testing the North muTr chamber "pigtail" calibration connections - MJL - 11/3/01
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We will use the North calibration system to pulse the "calibration" anode wires
via the "pigtail" connections to the calibration and sigHV-return posts on the
chambers and observe the induced signals on the cathodes.

A small calibration system with one driver board has been set up in a small
portable VME crate. Signals from a driver card come out on short patch
panel cables to the patch panel where they continue on a long calibration cable
to connect onto the pigtail with a round black connector at the chamber to be tested.
The long cable is about 70 feet long and just barely reaches the station-3 chamber
near the end of the clean tent. The calibration system sends a square pulse about
12 microseconds in length with an amplitude up to 10 volts or so. The induced cathode
pulse will also be a square pulse about 12 microseconds long (with a slight decay
in amplitude with time on the flat top) of about +5 millivolts.

The calibration system is configured via its arcnet connection using Andrew's
arcnet control program (an icon on the desktop called "ARCdriver") on the Windows PC.
The calibration menu is accessed through the "l" option in the menu. To configure
the calibration system from scratch (e.g. when it has been powered off) one would
"clear", "set defaults", "set dac" and then "set all drivers". The calibration
system is can be adressed on arcnet by the address of hex 80.
A hex value of 80 should be used for the "set dac" and a hex value of ffff should be
used for "set all drivers". Once this is done one should see all the green LED's on
the driver card on.

The trigger for the calibration system comes from the GTM using one of the mode
bit files with "CALI" in the name, e.g. GTM.MUTR_100HZ_CALI.gtm. To start the
GTM GUI contronl go to the LINUX PC and log into phnxmutr, then "cd test" and "go_gtm".
This should raise a GUI for GTM control. Load the calibration mode bit file,
do a "scheduler reset" and a "start", then a "glink reset". Once this is done the
fiber from the GTM into the calibration system should be triggering the system.
You should see the top "trigger" LED on the calibraton glink module flashing as it triggers.

Each gap in a chamber (3 for stations-1&2 and 2 for station-3) has one differential
signal from one output of the calibration system hooked to it. You should see induced
signals on all cathodes of all planes in the chamber. If the two cathode planes from
one gap are not showing an induced pulse (of ~+5 mV) then you should check the connection
of the pigtail cable to that gap. The specification of the connections is detailed
in a separate note. The cathode connectors on the chamber cards have the row of ground
pins closest to the PC board. Be careful to put on the connectors used to observe
the cathode signals on the scope in the correct orientation.