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

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 Signal
Port
Bit
Name
Direction
Description
U503 PORT(A) 0
2
LEFT IN
3
4
5
6
SPARE OUT
7
UNUSED
IN
HL1
IN
HL2
IN
SPARE
N/A
SPARE
N/A
+10 dB
OUT
HL1 and HL2 form a 2 bit
code of the HL selector
position.
HL2 HL1
Position 1 - 1
1
Position 2 - 1
0
Position 3 - 0
0
Position 4 - 0
1
LEFT and UNUSED form the 2
bit code of the Routing
Switch position.
UNUSED LEFT
Invalid - 0
0
Unused - 0
1
Right - 1
0
Left
-1
1
Not Used
Not Used
+10 dB (Extended Range)
Pad control. 0 = Pad Out
1 = Pad In
(Range
Extended)
Not Used
See Bit 2 - LEFT
U503 PORT(E) 3
FREQ1
IN
FREQ1-FREQ4 form the 4 bit
2
FREQ2
IN
code of the Frequency
1 FREQ3
IN
Selector position.
0 FREQ4 IN
LSB
MSB
SELECT FREQ FREQ4 FREQ3 FREQ2 FREQ1
12525 Hz 1 1 1 1
250 Hz- 1 1 1 0
500 Hz- 1 1 0 0
750 Hz- 1 1 0 1
1 KHz- 1 0 0 1
1.5KHz- 1 0 0 0
2 KHz- 1 0 1 0
3 KHz- 1 0 1 1
4 KHz- 0 0 1 1
6 KHz- 0 0 1 0
8 KHz- 0 0 0 0
Pos.12- 0 0 0 1
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