HP 2040D - Manual (Page 38)

Series 2040 Test System
Series 2040 Maintenance Manual V2.00 Diagnostics
37
GPIB/HPIB POWER SUPPLIES
The Series 2040 Test System may also contain one or more GPIB/HPIB Power
Supplies. These supplies communicate with each other and the computer via
an IEEE-488 bus. In addition, they use a Fault/Inhibit loop for voltage/current
protection and this loop also connects to the Testhead Power Supply
Controller.
Some of these supplies may have more than one output channel. In these
situations, each separate output of each GPIB/HPIB supply is assigned its own
channel or unit number. Programming is accomplished using Digalog’s
PowerUUT functional call. Over/under voltage/current limits for these supplies
and channels are listed in the “resource.cat” file. For programming purposes,
these power supplies act in the same manner as the Digalog UUT Product
Power Supplies.
Troubleshooting Hewlett-Packard Power Supplies
The fault/inhibit loop for the Hewlett Packard power supplies links each HP
power supply serially with each other and with the PSC board. It is completely
independent of the UUT P/S controllers’ (external) fault loop and the fault
loop for each non-HP GPIB power supply.
The PSC board will recognize a fault generated by the HP fault/inhibit loop
only if the registered power supply configuration (set up by TRMAN) contains
at least one HP power supply whose “resource.cat” entry has its “Fault
Capable” property set to “1.”
The “HPF” LED on the PSC board will turn off whenever an HP power supply
has either detected an internal error condition, such as overvoltage, or has
been “faulted” by the PSC board, but only after a HP power supply has been
programmed following a Testhead power-up or the TClear event.
The fault signal driving the HPF LED on the PSC is not latched. Also, if the
reset jumper shunt on the PSC board is installed, only the Proximity-Switch
LED will turn off when the Patchboard fixture handle is disengaged. It will
then turn back on when the handle has re-engaged. The PSC board will drive
its HP fault/inhibit loop connection low every time that it detects a fault from
any source whether or not any HP power supplies are registered or even
present.