National Instruments SCXI-1121 - Manual (Page 20)

Chapter 2 Configuration and Installation
SCXI-1121 User Manual 2-4 www.natinst.com
On Revision C or later modules, jumper W44 does not exist. SLOT0SEL*
is always buffered to the INTR* line.
Jumper W38
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 W32, the data acquisition board can read the Module
ID Register of the SCXI-1121. 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-1121 Cabling , for the pin equivalences of the
SCXI-1121 rear signal connector and the data acquisition board I/O
connector. This is the factory-default setting.
Position 3 disconnects SERDATOUT from the SCXIbus MISO line.
Jumper W32
On Revision A and B modules, jumper W32 should not be connected. On
Revision C or later modules, Position 1 connects a 2.2 k
Ω
pullup resistor
to the SERDATOUT line (factory-default setting), and Position 3 does not
connect the pullup resistor to the SERDATOUT line.
Using Jumpers W32 and W38
Set jumpers W32 and W38 as follows:
If the SCXI-1121 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-1121 is cabled to a data acquisition board, and the SCXI
chassis that the SCXI-1121 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-1121 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 multi-chassis adapters),
leave the jumpers in their factory default positions (both in position 1).
If the SCXI-1121 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 multi-chassis adapters), leave jumper