Teledyne LeCroy PC_AT 200 - Manual (Page 5)

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NOTE: These switches can also be controlled by software. In this case
the switches on the dip switch must be in the open position and the
software will control the open and closure of the switches. See the
software commands section for more details.
CURRENT MEASUREMENT
To measure the current being drawn by the UUT, just connect a voltmeter
to J5, polarity should be as shown on the board. Every Volt read by the
meter represent 1 Amp. So if the voltmeter reads 0.35, it represents
that the UUT is drawing 350 milliampere of current from +5V supply.
CURRENT LIMIT CIRCUITRY
Red LED's, when illuminated, indicate shorts or a very low voltage at the
output for their corresponding voltages. Green LED's when illuminated,
indicate voltages at their corresponding outputs. In the case of the +5V
short, from the UUT, the Active Extender will automatically switch the
current limit down to about 200 milliamperes and will continue to deliver
this current for troubleshooting purposes. In the case of shorts or
excessive current draw for the other voltages (-5V, +/-12V), the
resetable fuses will open up until the problem is corrected.
The current limit value for the +5V is set to 5 Amps with JP9 not
installed and 1 Amp with JP9 installed. Consult the factory for current
requirement other than 5 Amps.
EXTERNAL POWER SUPPLY
J6 or JP5 terminals can be used for the external power supply input. J6
is used with a ribbon cable for ease of interconnecting (see the pinout
on page 8). However, remember never to connect any other supply to these
inputs so long as you have JP1, JP2, JP3 and JP4 installed. In case you
want to use the external supply as an input you must remove these 4
jumpers in order not to cause any conflict with the bus voltages. These
jumpers are, however, independent from each other. For instance if you
would want to bring in only a +5V from the external supply and continue
to use the bus voltages for +12V and -12V and -5V, you would only need to
remove JP4.