Configuration and Installation
Chapter 2
SCXI-1100 User Manual
2-24
© National Instruments Corporation
Analog Output Signal Connections
Pins 1 through 6 and pin 19 of the rear signal connector are analog output signal pins. Pins 1 and
2 are AOGND signal pins. AOGND is an analog output common signal that is routed through
jumper W10 to the PGIA reference on the SCXI-1100. You can use these pins for a general
analog power ground tie point to the SCXI-1100 if necessary. In particular, when using
differential input data acquisition boards, such as the MIO boards, it is preferable to leave
jumper W10 in its factory setting or in position AB-R1 to avoid ground loops. With data
acquisition boards that are configured for referenced single-ended (RSE) measurements, set
jumper W10 in position AB-R0 to connect the SCXI-1100 ground to the data acquisition analog
ground. Pin 19, the OUTREF pin, is connected internally to the PGIA reference when jumper
W10 is in position AB-R2. Pins 3 through 6 are the analog output channels of the SCXI-1100.
Pins 3 and 4, or MCH0
±
, are a multiplexed output of the PGIA output and the temperature sensor
output. Pins 5 and 6, or MCH1
±
, are a direct connection of the temperature sensor to the rear
signal connector. Notice that the temperature sensor is located on the terminal block. For further
details on configuring the temperature sensor output, refer to the SCXI-1300 Terminal Block
section earlier in this chapter.
Warning: The SCXI-1100 analog outputs are not overvoltage protected. Applying external
voltage to these outputs can damage the SCXI-1100. National Instruments is not
liable for any damages resulting from such signal connections.
Digital I/O Signal Connections
Pins 24 through 27, 29, 33, 36, 37, and 43 constitute the digital I/O lines of the rear signal
connector. These pins are divided into three categories–the digital input signals, the digital
output signals, and the digital timing signals.
The digital input signals are pins 24, 25, 27, 29, 33, and 37. The data acquisition board uses
these pins to configure the SCXI module when the module is under data acquisition board
control. Each digital line emulates the SCXIbus communication signals as follows:
•
Pin 25 is SERDATIN and is equivalent to the SCXIbus MOSI serial data input line.
•
Pin 27 is DAQD*/A and is equivalent to the SCXIbus D*/A line. Pin 27 indicates to the
module whether the incoming serial stream on SERDATIN is data (DAQD*/A = 0), or
address (DAQD*/A = 1) information.
•
Pin 29 is SLOT0SEL* and is equivalent to the SCXIbus INTR* line. Pin 29 indicates
whether the data on the SERDATIN line is being sent to Slot 0 (SLOT0SEL* = 0) or to a
module (SLOT0SEL* = 1).
•
Pins 24 and 33 are the digital ground references for the data acquisition board digital signals
and are tied to the module digital ground.
•
Pin 37, SERCLK, is equivalent to the SCXIbus SPICLK line and clocks the serial data on the
SERDATIN line into the module registers.
The digital output signal is pin 26:
•
Pin 26 is SERDATOUT and is equivalent to the SCXIbus MISO line when jumper W5 is in
position 3.
