Configuration and Installation
Chapter 2
SCXI-1160 User Manual
2-6
© National Instruments Corporation
is in which slot. In addition to reading the Module ID Register, the MISO line on the SCXI-1160
can read the Status Register, which indicates the status of the relays. National Instruments
software uses this feature.
The SERDATOUT line is driven with an open-collector driver, which is a driver that actively
drives low or goes to a high-impedance state, relying on a pullup resistor to make the signal line
go high. When using a single chassis, set both jumpers W1 and W5 in position 1 on the
SCXI-1160 that is connected to the data acquisition board. In this setting, the module drives
MISO to SERDATOUT and connects the necessary pullup resistor to the SERDATOUT line.
When using multiple chassis, set jumper W5 in position 1 on all of the SCXI-1160s that are
cabled to the data acquisition board. Set jumper W1 in position 1 on only one of the SCXI-1160s
that are cabled to the data acquisition board. It does not matter which of the SCXI-1160s that are
cabled to the data acquisition board has the pullup connected. Set jumper W1 in position 3 on all
of the other SCXI-1160 modules that are cabled to the data acquisition board. If too many pullup
resistors are attached to the SERDATOUT line, the drivers cannot drive the line low. See Table
2-1 for the description and configuration of the jumper settings.
Table 2-1. Digital Signal Connections and Jumper Settings
Jumper
Description
Configuration
W1
W1
W5
W5
Parking position
Factory Setting–Connects pullup to
SERDATOUT
Parking position
Factory setting–Connects MISO to
SERDATOUT
•
•
•
3
2
1
•
•
•
3
2
1
•
•
•
3
2
1
•
•
•
3
2
1
(continues)