A 3 1 Handler Interface (Opt.202) Service Sheet 4 - A - Agilent Technologies 4284A Service Manual

4-20. A31 HANDLER INTERFACE (OPT.202) SERVICE SHEET
4-20-1. CIRCUIT DESCRIPTION
The A31 handler interface board consists of photo couplers, and peripheral interface adapt-
ers (PIAs).
[ Photo Couplers ]
Photo couplers A31U1 through A31U14 opto-isolate the input and output signals. T h e n
timing of the input/output signals is determined by setting jumpers A31W3 through A31W13.
For more detail information about the input/output signals and the jumpers, refer to the
handler interface operation note in the HP 4278A Operation Manual.
[ Peripheral Interface Adapters ]
Peripheral interface adapters ( PlAs ) A31U19 and A31U20 interface between the A7 CPU
board and the A31 board.
4-20-2. TROUBLESHOOTING AIDS
The test points are listed in Table 4-A31-1.
Test Point
Signal Name
A31TP1
A31TP2
A31TP3
A31TP4
4-20-3. REPLACEABLE PARTS LISTS
The replaceable parts for the A31 Handler Interface board are listed in Table 4-A31-2.
4-20-4. COMPONENT LOCATIONS
The component locations on the A31 Handler Interface board and the board connector pin
assignments are shown in Figure 4-A31-1.
4-20-5. SCHEMATIC DIAGRAMS
The schematic diagram of the A31 handler interface board is shown in Figure 4-A31-2.
Table 4-A31-1. Test Point List
Description
GND Ground line
+5V +5 V DC
BE 792 kHz Clock signal
START IN signal
4-A31-1
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