Keyscan CA250B - Control Board Voltage Test Points

Keyscan Inc. – Technical Guide (PC109x - 04.15)
84
Control Board Voltage Test Points
The following table lists correct voltages for the control board’s test points. Be sure to review the notes
opposite the appropriate voltage test points to comply with proper measuring techniques.
Voltmeter Connections
 Voltmeter set to VDC
 V-Ω (ohms) to test points
 Com to ground lug in metal enclosure
Table 16 – Control Board Test Points - Voltages
Board Test Point
Voltage
Instructions/Notes
Reader Terminal
D1 WHT
(+) 5 VDC
White data 1 – if reader connected
D0 GRN
(+) 5 VDC
Green data 0 – if reader connected
PWR RED
(+) 12VDC
Red DC out
TP1
(+) 13.5 VDC
Reader power
TP2
(+) 13.5 VDC
ACU power
TP3
(+) 13.5 VDC
ACU power after circuit protector
TP4
(+) 5 VDC
TP5
(+) 3.3 VDC
Input Points
Input points with open circuit
(+) 5 VDC
Input points shorted to common
return
0 VDC