National Instruments SCXI-1121 Manuel D’Utilisation

A1, B1, C1, D1, A2, 
D2,A3, B3, C3, D3, A4, 
D4, A5, B5, C5, D5, A6, D6

GUARD

Guard—Shields and guards the analog bus lines 
from noise.

B2

AB0+

Analog Bus 0+ —Positive analog bus 0 line. Used 
to multiplex several modules to one analog signal.

C2

AB0–

Analog Bus 0– —Negative analog bus 0 line. Used 
to multiplex several modules to one analog signal.

C13-C17, A21, B21, C21, 
D21

CHSGND

Chassis Ground—Digital and analog ground 
reference.

C18

RSVD

Reserved.

A19

RESET*

Reset—When pulled low, reinitializes the module 
to its power-up state. Totem pole. Input.

B19

MISO

Master-In Slave-Out—Transmits data from the 
module to the SCXIbus. Open collector. I/O.

C19

D*/A

Data/Address—Indicates to the module whether 
address information or data information is being 
sent to the module on MOSI. Open collector. I/O.

D19

INTR*

Interrupt—Active low. Causes data that is on 
MOSI to be written to the Slot-Select Register in 
Slot 0. Open collector. Output.

A20, B20, C20, D20

 V–

Negative Analog Supply— –18.5 to –25 V.

A22, B22, C22, D22

V+

Positive Analog Supply— +18.5 to +25 V.

A23, D23

+5 V

+5 VDC Source—Digital power supply.

B23

SPICLK

Serial Peripheral Interface (SPI) Clock—Clocks 
the serial data on the MOSI and MISO lines. Open 
collector. I/O.

C23

MOSI

Master-Out Slave-In—Transmits data from the 
SCXIbus to the module. Open collector. I/O.