Input/Output (I/O) Port Designations - Welch Allyn Grason-Stadler GSI 17 Series Service Manual

The Left/Right Control
The FM/Pulsed/Steady Control
The Subject Response Switch
The Calibration/Normal Mode Switch
The Calibration/Diagnostic Mode Dip Switch(s)
8.6

INPUT/OUTPUT (I/O) PORT DESIGNATIONS

Physical
Bit
Port
U503 PORT(A) 0
2
3
4
5
6
7
U503 PORT(E) 3
2
1
0
Signal
Direction
Name
IN
HL1
IN
HL2
LEFT IN
SPARE
N/A
SPARE
N/A
OUT
+10 dB
SPARE OUT
IN
UNUSED
FREQ1 IN
IN
FREQ2
IN
FREQ3
FREQ4 IN
SELECT FREQ FREQ4 FREQ3 FREQ2 FREQ1
125 25 H z
250 Hz-
500 Hz-
750 Hz-
1 KHz-
1.5KHz-
2 KHz-
3 KHz-
4 KHz-
6 KHz-
8 KHz-
Pos.12-
Description
HL1 and HL2 form a 2 bit
code of the HL selector
position.
HL2
Position 1 - 1
Position 2 - 1
Position 3 - 0
Position 4 - 0
LEFT and UNUSED form the 2
bit code of the Routing
Switch position.
UNUSED LEFT
Invalid - 0
Unused - 0
Right
Left
- 1
Not Used
Not Used
+10 dB (Extended Range)
Pad control. 0 = Pad Out
1 = Pad In
(Range
Not Used
See Bit 2 - LEFT
FREQ1-FREQ4 form the 4 bit
code of the Frequency
Selector position.
LSB
1 1
1 1
1 1
1 1
1 0
1 0
1 0
1 0
0 0
0 0
0 0
0 0
HL1
1
0
0
1
0
1
0
1
Extended)
MSB
1 1
1 0
0 0
0 1
0 1
0 0
1 0
1 1
1 1
1 0
0 0
0 1