Fluke Biomedical 945A - Manual (Page 60)

Data Entry (Read Only)
Octal buffer U36 functions as an interface to supply the status of the switches for data entry to the internal
data bus address (4002). The data entry read functions are shown in Table 4-20. The function switch
logic is shown in Table 4-21
Table 4-20. Data Entry Read Functions
Data Bit Function
D0 Enter Switch (Active Low)
D1 Value Select Switch (Active Low)
D2 Digit Select Switch (Active Low)
D3 (Not Used)
D4 (16 position function switch, see Table 4-21)
D5 (16 position function switch, see Table 4-21)
D6 (Not Used)
D7 (Not Used)
Table 4-21. Function Switch Logic
Hex
Data D7 D6 D5 D4 Position Function
F 1 1 1 1 0 High
E 1 1 1 0 8 Auto Zero Test
D 1 1 0 1 1 Warn
C 1 1 0 0 9 Loop Test Mode
B 1 0 1 1 4 Analog Full Scale Value
A 1 0 1 0 C Undefined
9 1 0 0 1 5 Calibration Factor
8 1 0 0 0 D Undefined
7 0 1 1 1 2 Overrange
6 0 1 1 0 A Undefined
5 0 1 0 1 3 Underrange
4 0 1 0 0 B Undefined
3 0 0 1 1 6 Undefined
2 0 0 1 0 E Undefined
1 0 0 0 1 7 Analog Low Scale Value
0 0 0 0 0 F Undefined
Sensitivity Select (Read Only)
Octal buffer U42 functions as an interface to provide the status of the sensitivity selection jumpers, mode
jumpers, anti-jam bit data, and serial data from E2 PROM to the internal data bus and MPU. U42
responds to address 4008. The sensitivity read functions are listed in table 4-22.
4-36