
NI 9757 User Manual |© National Instruments |3
Exhaust Gas Oxygen (UEGO) sensors. Narrow band sensors may also be referred to as Exhaust
Gas Oxygen (EGO) sensors.
NI recommends using the NI 9923 Connector Kit for connecting to the NI 9757. The NI 9923
provides proper strain relief for NI 9757 connections. Visit ni.com/info and enter Info Code
O2MODULE for more information on parts and accessories for the NI 9757.
Powering the Module
The NI 9757 requires power from each of the following sources:
• The CompactRIO backplane male high density DSUB 15-pin (HD15) connector, which
mates with the female HD15 connector on the module. This power source provides a
regulated 5 V and ground to various digital logic functions. The CompactRIO 5 V source
is active whenever the CompactRIO or R Series Expansion Chassis is properly powered.
You can power the NI 9757 only at the HD15 connector by plugging it into a CompactRIO
or R Series Expansion Chassis. Do not connect the HD15 connector to any other device.
• The external DB-37 connector, the terminals of which are labeled BATT (10) and
GND (29). A typical power source is an automotive 12 V battery system, but the NI 9757
can accept power from a range of 6 V to 32 V. The LSU 4.x wide-band sensors will only
operate when the power supply is in the range of 8 V to 16.5 V. The module is reverse
battery protected to -18 V.
Without sensors connected and enabled, the NI 9757 requires up to 100 mA from the external
supply. The external power source must be capable of powering the sensor heaters, which may
require up to 12 A if all channels are in use. Each sensor heater requires approximately 2 A
during the first 30 seconds of operation and approximately 1 A thereafter. The UEGO sensor
heaters are powered and controlled directly from the NI 9757. The EGO sensor heaters are
powered externally and do not require heater control by the NI 9757.
The NI 9757 external power ground and CompactRIO backplane power ground are isolated and
have no internal connection.
Caution The external battery supply input terminals are reverse voltage polarity
protected to -18 V. Connecting power to the NI 9757 in reverse polarity at voltages
greater than -18 V will result in damage. This event is not covered by the warranty.
Platform Compatibility
NI Powertrain Control modules require a hardware support system to function. You cannot use
the modules independently or interfaced with third-party devices at the backplane HD15
connector. NI Powertrain Control modules are compatible with the following National
Instruments platforms:
• CompactRIO, which consists of a CompactRIO controller, chassis, or integrated
controller/chassis.
• NI PXI, which consists of any NI PXI chassis, NI PXI RT controller, and NI PXI-78xxR
R Series FPGA card. The NI Powertrain Control modules insert into an NI R Series