National Instruments 320682C

Chapter 10 Easy I/O for DAQ Library

• If you are using a Lab-PC+, DAQCard-500/700/1200, DAQPad-1200, PC-LPM-16:

These devices can only sample input channels in descending order, and you must end with

channel 0 ("3:0"). If you are using a Lab-PC+ or 1200 product in differential mode, you

must use even-numbered channels ("6,4,2,0").

• If you are using a DAQPad-MIO-16XE-50:

You can read the value of the cold junction compensation temperature sensor using the

following string as the channel:

"cjtemp"

• If you are using SCXI:

You can address SCXI channels when you attach one or more SCXI chassis to a plug-in data

acquisition board. If you operate a module in parallel mode, you can select a SCXI channel

either by specifying the corresponding onboard channels or by using the SCXI channel

syntax described below. If you operate the modules in multiplexed mode, you must use the

SCXI channel syntax.

The SCXI channel syntax is as follows:

• "OB1!SCx!MDy!a" /* channel a on the module in slot y of the chassis with

ID x is multiplexed into onboard channel 1 */

• "OB0!SCx!MDy!a:b" /* channels a through b inclusive on the module in slot

y of the chassis with ID x is multiplexed into onboard channel 0 */

SCXI channel ranges cannot cross module boundaries. SCXI channel ranges must always

increase in channel number.

The following examples of the SCXI channel syntax introduce the special SCXI channels:

• "OB0!SCx!MDy!MTEMP" /* The temperature sensor configured in MTEMP mode

on the multiplexed module in slot y of the chassis with ID x. */

• "OB1!SCx!MDy!DTEMP" /* The temperature sensor configured in DTEMP mode

on the parallel module in slot y of the chassis with ID x. */

• "OB0!SCx!MDy!CALGND" /* (SCXI-1100 and SCXI-1122 only) The grounded

amplifier of the module in slot y of the chassis with ID x. */

• "OB0!SCx!MDy!SHUNT0" /* (SCXI-1121, SCXI-1122 and SCXI-1321 only) Channel

0 of the module in slot y of the chassis with ID x, with the shunt resistor

applied. */

• "OB0!SCx!MDy!SHUNT0:3" /* (SCXI-1121, SCXI-1122 and SCXI-1321 only) Channel

0 through 3 of the module in slot y of the chassis with ID x, with the

shunt resistors applied at each channel. */