User Manual

2
Installation
42
CrossCheck CDPD Mobile Unit Manual
2.9.8
Outputs (XP0 to XP2)
The CrossCheck CDPD features three discrete outputs (XP0–XP2) for
driving external devices such as relays.
• When inactive (use state), the discrete outputs are tied to vehicle
battery voltage (nominally 12 VDC) through a 15 kOhm
resistor.
• When active, the outputs are shorted to ground through a
bipolar junction transistor. In the active (low) state, the outputs
can sink up to 200 mA.
Figure 2.21 shows a diagram of a discrete output.
Figure 2.21 Output Circuit Diagram
Output Inactive:
15 kOhms through V
vehicle-battery
Output Active:
Tied to ground through a saturated bipolar
junction transistor, V
out
1.5 VDC at
200 mA; V
out
< 0.5 VDC at
10 mA
Output Protection:
Protected against direct shorts to ground
Output Sink Current
Capability
Up to 200 mA
15K
36V
0.01µF
0.2A
470pf
Output
Vbatt