User's Manual

NXC-I/O10 Input/Output Control Card
13
NetLinx Cardframe, Control Cards, and NetModules - Operation Reference Guide
Setting the Voltage Clamp Jumper (+12V or Open)
Set the V- Clamp jumper (J31) to +12 V (default) to clamp any voltage connected to I/O ports 1-10 to 12 V.
Set to Open for connections that will draw more than 12 V.
Remember, the +12 V and OPEN settings are only enabled when the I/O ports are set to SW mode. The V-Clamp jumper
settings are described below:
When this jumper is Open, it is the technician's responsibility to clamp the external source relay anytime the voltage
exceeds 12 V. The source relay should always be clamped if the voltage exceeds 12 V. Contact the relay manufacturer to
determine the size of the diode in the source relay.
In switch mode, the A terminals are connected to the NetLinx Controller's ground.
Sources that require isolation from the Controller's ground should use voltage mode,
and provide switched DC power for sensing as required.
+12 V mode setting
(default)
Use the default setting for all loads that require less than 12 V.
Open mode setting When this jumper is set to Open, and an I/O port is used as an output, the
I/O port is rated at 85 mA @ 28 VDC.