HP 8642A - Page 290

Model 8642A/B
Adjustments
5-3. CORRECTION DATA SPECIAL FUNCTIONS
Identifying the Contents of the A20
The following is a procedure to display and identify the contents of the A20 Board.
1. Switch the HP 8642 to Standby.
2. Plug the A20 on to A3J3.
3. Switch the HP 8642 ON.
4. Key in: |SHIFT| [SPCT] (5| to enter service mode.
5. Key in: [4 8 Hz to display the Module ID numbers corresponding to Valid Cal Data in the A20
Board.
The A20 board can be thought of as having 10 memory locations. The address of each location,
(numbered 0 through 9), is the Module ID Number. Each memory location will either contain
Valid Cal Data or it will be blank. The A20 addresses that contain Valid Cal Data will now be
displayed. Some examples of the HP 8642 display are shown below. Refer to Table 5-4 to cross
reference the A20 addresses (Module ID Numbers) to the Memory Contents.
A20 containing HP 8642A Cal Data Backup: VALID CAL= 01234 6 8 9 .U619
VALID CAL= 567 .U619
A20 containing HP 8642B Cal Data Backup: [VALID CAL= 01 2 345 6789 AJ619
A20 provided with Al9 exchange module:
A20 provided with A6 exchange module:
(1)
A20 containing no data:
VALID CAL=
.U619
VALID CAL= 0
.U619
Tahh
ID Number
0
1
2
3
4
5
6
7
8
9
■ 5-4. Module ID Numbers.
Memory Contents
Model #, Serial #, Options
A11 Cal Data
A12 Cal Data
A6 Cal Data
A13 Cal Data
A19 Doubler Cal Data
A16 or A19 Attenuator Cal Data
A19 Rev. Pwr. Protect. Cal Data
A14 Cal Data
A2 Cal Data
(1)
In a newly initialized A20 board there will be data stored in location 0. The data will be Model #: HP 864-, Serial #:
and no options.
5-5