Chapter 4
Theory of Operation
4-6
ni.com
Figure 4-4.
Block Diagram of SCXI-1317 and SCXI-1521/B Combination
SCXI-1317
Terminal Block
Screw
Terminals
to
Field
Wiring
Gain x4,
10 Hz Filter
Null
Compensation
Fine
Null
Compensation
Fine
Shunt
Calibration
Switch
QTR 0
EX 0 +
Quarter-Bridge
Completion
Quarter-Bridge
Completion
SCXI-1521/B Module
Analog Multiplexer
Scan
Clock
Rear Signal Connector
SCXIbus Connector
Buffer
Digital Interface
and Control
Analog Bus
Switch
Multiplexer
Control
To
Analog
Bus
Excitation
Voltage
Reference
Excitation
Voltage
Setting
CH 0 +
CH 0 –
Signal Conditioning (see above)
Out 0
Out 23
Out 5
EX(0-5)
ISEN(0-5)
Out 18
EX(18-23)
ISEN(18-23)
Signal Conditioning
AI 0
QTR 5
EX 5 +
AI 5
QTR 23
EX 23 +
AI 23
EX0
ISEN5
ISEN0
EX5
+
Gain x4,
10 Hz Filter
–
Shunt Cal
Resistor
Shunt
Calibration
Switch
Shunt Cal
Resistor
Gain
x10.5
Gain
x10.5
Output
Amp
–
+
Output
Amp
–
+