Troubleshooting The A4 Local Logic Assembly - Agilent Technologies 11713A Operating And Service Manual

Troubleshooting the A4 Local Logic Assembly

The A4 local logic assembly contains a remote/local flip-flop, an A or B
flip-flop, a four-line to ten-line decoder, a local lockout flip-flop, listen
flip-flop, 10 two-line to one-line multiplexers, and the required circuitry
to generate a clock signal to control the operation of the four- to ten-line
decoder.
To Troubleshoot the A4 Local Logic Assembly
1. Make sure that the A3 latch, A5 GPIB, and A7 switch board
assemblies are functioning properly before troubleshooting the A4
local logic assembly.
2. If any of the following conditions cannot be met, replace the A4 local
logic assembly.
a. Turn the driver off and then on. The local light should be on. The
local light should be on.
b. To check the driver in remote operation, use an appropriate
controller to execute the following commands.
Command
a
REMOTE 728
LOCKOUT 7
LOCAL 7
OUTPUT 728;"Al2345678"
OUTPUT 728;"B12345678"
a. Factory preset GPIB address
Assembly Overview
The remote/local flip-flop is programmed through the GPIB circuitry on
the A5 handshake and data input assembly. If the local lockout flip-flop
is set to a high, the remote local flip-flop cannot be set to local via the
A7 front panel LOCAL pushbutton. In all other cases the A7 local
pushbutton will set the instrument to local.
In local operation, the 10 two-line to one-line multiplexers are set to
propagate and invert the outputs of the monostable multivibrators from
the A7 front panel assembly. The outputs become the clocks for the A3
latch assembly flip-flops. Bus commands determine the state of the A or
B flip-flop which controls the output state of the instrument.
Servicing the Attenuator/Switch Driver
Troubleshooting the A4 Local Logic Assembly
Desired Outcome
The remote light is on and the local light off.
Press the local button. Nothing happens.
The local operation is locked out.
The local button regains control.
All attenuator lights should be on.
All attenuator lights should go off.
11713A Operating and Service Manual 8-17