Chapter 2
Configuration and Installation
© National Instruments Corporation
2-5
SCXI-1120 User Manual
Jumper W44
On Revision A and B modules, position 1 connects, after buffering, SLOT0SEL* to the SCXIbus
INTR* line. This is the factory-default setting and should not be changed. In this setting, the
data acquisition board controls the SCXIbus INTR* line. See the Timing Requirements and
Communication Protocol section later in this chapter, and Chapter 5, Programming, for
information on the use of the INTR* line. See Appendix E, SCXI-1120 Cabling, for the pin
equivalences of the SCXI-1120 rear signal connector and the data acquisition board I/O
connector.
Position 3 is reserved and should not be used.
On Revision C and later modules, jumper W44 is not loaded. SLOT0SEL* is always buffered to
the INTR* line.
Jumper W43
Position 1 connects, after buffering, the SCXIbus MISO line to the SERDATOUT pin of the rear
signal connector. In this setting, along with the proper setting of jumper W42, the data
acquisition board can read the Module ID Register of the SCXI-1120. This is the factory-default
setting. See the Timing Requirements and Communication Protocol section later in this chapter,
and Chapter 4, Register Descriptions, for information on reading the Module ID Register. See
Appendix E, SCXI-1120 Cabling, for the pin equivalences of the SCXI-1120 rear signal
connector and the data acquisition board I/O connector.
Position 3 disconnects SERDATOUT from the SCXIbus MISO line.
Jumper W42
On Revision A and B modules, jumper W42 should not be connected. On Revision C and later
modules, position 1 connects a 2.2 k
Ω
pullup resistor to the SERDATOUT line. Position 3 does
not connect the pullup resistor to the SERDATOUT line.
Using Jumpers W42 and W43
If the SCXI-1120 is not cabled to a data acquisition board, the positions of these jumpers do not
matter, so leave them in their factory-default positions (both in position 1).
If the SCXI-1120 is cabled to a data acquisition board, and the SCXI chassis that the SCXI-1120
is in, is the only SCXI chassis cabled to that data acquisition board, leave the jumpers in their
factory-default positions (both in position 1).
If the SCXI-1120 is cabled to a data acquisition board, and there are multiple SCXI chassis
cabled to that data acquisition board with shielded cables (you are using SCXI-1346 shielded
cable multichassis adapters), leave the jumpers in their factory-default positions (both in
position 1).
If the SCXI-1120 is cabled to a data acquisition board, and there are multiple SCXI chassis
cabled to that data acquisition board with ribbon cables (you are using SCXI-1350 multichassis
adapters), leave jumper W43 in its factory-default position (position 1). On all but one of the
SCXI-1120s that are cabled to the data acquisition board, move jumper W42 to position 3. It
does not matter which of the SCXI-1120 modules that are cabled to the data acquisition board
has jumper W42 set to position 1. If you have different types of modules cabled to the data
