Teledyne LeCroy AGPAX - Manual (Page 4)

4
OPERATION
Using this Active Extender board is no different than using a regular extender board. However, the extra features that
the Active Extender have to offer, are explained below:
ON-OFF
To insert or remove any Unit-Under-Test into and out of the Active Extender, make sure that the Active Extender is
turned Off, if the system power is to stay On. There are two ways to turn the Active Extender power On and Off. 1)
The mechanical toggle switch. 2) External control signal (via Parallel Port).
AGPAX boards may be controlled via parallel port interface. Turn the On-Off switch to the Off position, plug a
parallel cable between the system port and the board(s) and use the system parallel port address to turn the board(s) On
and Off.
Two AGPAX boards in a system may be controlled independently, if so desired. Jumper JP15 on the board may be
used to configure each board to be turned On and Off by a different bit of the parallel port. For example board One is
set to be controlled with JP15 installed and board Two is set to be controlled with JP15 removed. Low level for each bit
will turn the board On and Hi will turn the board Off.
Examples, assuming the system parallel port address is set at 378:
outp (0x378, 0x05) Will turn board One On.
outp (0x378, 0x50) Will turn board Two On.
outp (0x378, 0xff) Will turn both boards Off .
POWER-ON RESET
Each time the Active Extender board is turned Off and then On, reset signal will be generated from the extender to the
Unit-Under-Test automatically. The duration of this reset is 200 milliseconds. The reset to the Unit-Under-Test is also
activated every time there is a reset from the bus.
CURRENT MEASUREMENT
To measure the current being drawn by the Unit-Under-Test, just connect a voltmeter to J3. Every Volt read by the
meter represent One Amp. So if the voltmeter reads 0.35, it represents that the Unit-Under-Test is drawing 350
milliampere of current. J3 terminals are marked for Ground, 5I, 3CI, and VDQI.
CURRENT LIMIT CIRCUITRY
Red LEDs, when illuminated, indicate a short or a very low voltage. Green LEDs when illuminated, indicate voltages
at their corresponding outputs. In the case of the short for the +5V, +12V, VCC3, and VDDQ from the
Unit-Under-Test, the Active Extender will shutdown immediately.
The current limit value for the +5V, VCC3, and VDDQ are set to 5 Amps.