Chapter 2
Using the SCXI-1530/1531
2-6
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The maximum scan rate for the SCXI-1530/1531 module in parallel mode
is 125 kscans/s or the maximum scan rate of the DAQ device, whichever is
lower. There is no maximum scan rate for the SCXI-1530/1531 module
when operated in parallel mode with sample-and-hold disabled.
Operating in Multiplexed Mode
You can configure the SCXI-1530/1531 to operate in multiplexed mode as
described in
Configuring the SCXI-1530/1531
Configuring the SCXI-1530/1531
. In multiplexed mode, you can multiplex
all input channels of the SCXI-1530/1531 into one output channel that is
read by the National Instruments DAQ device.
Theory of Multiplexed Hardware Operation
When you configure a module for multiplexed mode operation, the
multiplexed signals routed to the DAQ device depend on which module is
cabled to the DAQ device in the SCXI system. If the module being scanned
is not directly cabled to the DAQ device, the module sends its signals
through the SCXIbus to the cabled module. The cabled module, whose
routing is controlled by the SCXI chassis, routes the SCXIbus signals to the
DAQ device through the MCH0 signal on the rear signal connector. See the
rear signal connector in Figure 2-4. If the DAQ device scans the cabled
module, the module routes its input signals through the MCH0 signal on the
rear signal connector. The power of SCXI multiplexed scanning is its
ability to route many input channels, spanning many modules, to a single
channel on the DAQ device.
Note
In multiplexed mode, you must connect the DAQ device to either the
SCXI-1530/1531 module or an SCXI-1140 module if one is in the chassis.