A20 Hp-Ib Interface Service Sheet - Agilent Technologies 4284A Service Manual

4-18. A20 HP-IB INTERFACE SERVICE SHEET

4-18-1. CIRCUIT DESCRIPTION
The A20 HP-IB Interface board handles all HP-IB interface functions. T h e HP-IB Interface
board controls the handshaking between the Microprocessor and external HP-IB controlled
equipment.
4-18-2. TROUBLESHOOTING AIDS
The test points are listed in Table 4-A20-1.
Test Point
A2OTP1
A2OTP2
A2OTP3
A2OTP4
4-18-3. REPLACEABLE PARTS LISTS
The replaceable parts for the A20 HP-IB Interface board are listed in Table 4-A20-2.
4-18-4. COMPONENT LOCATIONS
The A20 HP-IB Interface board component locations are shown in Figure 4-A20-1.
4-18-5. SCHEMATIC DIAGRAMS
The A20 HP-IB Interface board schematic diagram is shown in Figure 4-A20-2.
Table 4-A20-1. A20 Test Points
Signal Name
GNU
+5V
LDS
4M1-11
4-A20-1
Description
Ground reference f o r t h e + 5 V digital
supply
+5 V digital supply
Lower Data Strobe Signal
4 MHz is counted down from the A7
/ C I X /6M Hz
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