Date: Tue, 20 May 2003 13:36:21 -0700
From: "Rodriguez, Raymond R." <ray_rod@SLAC.Stanford.EDU>
To: "Su, Dong" <sudong@SLAC.Stanford.EDU>,
     "Halyo, Valerie" <valerieh@SLAC.Stanford.EDU>
Cc: "O'Grady, Christopher P." <cpo@SLAC.Stanford.EDU>,
     "Innes, Walter" <walt@SLAC.Stanford.EDU>
Subject: RE: One more crate to handle

Okay, this is tedious at best but considering the consequences when shorting
hundreds of amps it may be worth the effort.

Some of the things to remember...

1. This only works if the power supply is in the NORMALMODE all settings will
be ignored in TESTMODE.

2. The limits entered reside in the power supply and not the fan tray or crate
so one could confuse one self when moving power supplies around and suddenly
getting over current warnings. This is said as we are all known to use test lab
supplies as spares for the real system.

Now how do you do this......each voltage available on the power supply that you
are utilizing has a minimum output voltage UMIN, a maximum output voltage UMAX
and a maximum current IMAX. There are no local settings for the fans and
temperatures.

1. Switch the fan tray on, select channel whose limits you want to set with the
mode-switch.

2. Switch the power and mode switch both simultaneously (hold Mode switch
down and powerswitch up - SD Oct/04) and hold for about 10 seconds. The 
controlling menu will be displayed.

3. Select the controlling measurement to be set with the mode switch. IMAX,
UMIN or UMAX.

4. Push the power switch up. The value should flash and may now be changed with
the mode-switch.
mode-switch up   = increase value
mode-switch down = decrease value

5. Push the power switch down. The exits the controlling menu.

Return to step 3 to select another value to set or go to step 6.
6. Push the power switch down. This should exit programming mode and the supply
should be off.

I may need to refine these instructions but it is a start and I encourage
everyone using one of these crates in a test stand environment to set some
reasonable values. I realize that the nature of a test stand is that it changes
but rarely do we change by tens of amps. For example the IOCTEST 6U VME crate
in the lab has a 200 amp 5V supply but with 7 cards installed only draws 9 amps
on the +5V. A reasonable setting in this case might be 20 Amps thus we don't
draw all 200 when 2 pins get shorted and start a real fire.

Good luck, Ray