National Instruments SCXI-1121 Manuel D’Utilisation

to MCH0 through MCH3 on the rear signal connector. The module is 
disconnected from Analog Bus 0 and disabled from scanning.

This section describes how to program the SCXI-1121, either alone or in 
conjunction with other modules, to make single-channel, or nonscanned, 
measurements.

In order to perform a parallel output measurement, you must cable the 
SCXI-1121 rear signal connector to a data acquisition board with each 
output connected to a different data acquisition board channel. See 
Chapter 2, 

, for more information. For 

information on how to make the voltage measurement with your data 
acquisition board, consult your data acquisition board user manual. 
Remember to account for the gains of both the SCXI-1121 and the data 
acquisition board when calculating the actual voltage present at the input of 
the SCXI-1121.

To measure one of the four differential input channels to the SCXI-1121, or 
the DTEMP line if the module has been configured appropriately, perform 
the following steps:

1.

Write the binary pattern 

000XXX00 XX000000

 to the SCXI-1121 

Configuration Register. Notice that this can be the RESET state.

2.

Measure the voltage with the data acquisition board.

In order to perform a direct multiplexed output measurement, you must 
cable the SCXI-1121 rear signal connector to a data acquisition board. 
See Chapter 2, 

, for more information. For 

information on how to make the voltage measurement with your data 
acquisition board, consult your data acquisition board user manual. 
Remember to account for the gains of both the SCXI-1121 and the data 
acquisition board when calculating the actual voltage present at the input 
of the SCXI-1121.