National Instruments SCXI: Part 7

This is part 7 in our blog series about the National Instruments SCXI platform! Part 7 will discuss the remaining front-mounting SCXI terminal blocks not previously discussed in part 6. If you are new to our blog, you can read the previous 6 blog posts about NI SCXI before continuing!

The NI SCXI-1317 is a front-mounting terminal block designed for use with the SCXI-1521 and SCXI-1521B quarter-bridge strain gage input modules. This 24-channel terminal block delivers three terminals for every quarter-bridge strain gage channel. These terminals include excitation +, analog in, and quarter-bridge.

The SCXI-1320 is a general-purpose terminal block created for connecting signals to the SCXI-1120, SCXI-1120D, SCXI-1121, SCXI-1125, and SCXI-1126 modules. This terminal block includes an onboard temperature sensor for measuring the reference junction temperature when utilizing thermocouples.

 

 

If you are using strain gauge transducers with the SCXI-1121, you can add offset nulling and shunt calibration capability to your system with the SCXI-1321 terminal block. With a trimming potentiometer on the front panel of the SCXI-1321, you can manually null out the offset voltage of bridge transducers. Every channel includes shunt calibration circuits, controllable as a group from software. When activated, a switch connects a 301 k Ohm shunt resistor (Rcal) in parallel with the strain gauge. Both the nulling resistor (Rnull) and the shunt resistor (Rcal) are socketed, so you can easily change their values to adjust the nulling range and shunt value.

 

 

The SCXI-1322 is the terminal block necessary to connect signals to the SCXI-1122 module. The SCXI-1322 is a general-purpose terminal block with an onboard temperature sensor for cold-junction compensation. The SCXI-1325 is a terminal block with 26 screw terminals for signal connections to the SCXI-1124 module. The SCXI-1326 is a high-voltage terminal block with 48 screw terminals for signal connections to the SCXI-1162, SCXI-1162HV, SCXI-1163, and SCXI-1163R modules.

With the SCXI-1327, you can extend the input range of the SCXI-1120, SCXI-1120D, SCXI-1121, and SCXI-1125 modules to 300 VDC or 300 Vrms. You can also utilize the SCXI-1327 to extend the threshold level of the SCXI-1126 module from 5 V up to 300 V. The extended input voltage range is activated or deactivated on a per-channel basis using switches within the SCXI-1327. The SCXI-1327 also contains an onboard temperature sensor for cold-junction compensation with thermocouples.

 

 

If you are using thermocouples with the SCXI-1120, SCXI-1120D, SCXI-1121, or SCXI-1125 you can use the SCXI-1328 for maximum preciseness. The SCXI-1328 has isothermal construction that reduces errors caused by thermal gradients between terminals and the extremely precise cold-junction sensor.

The National Instruments SCXI-1331 is a general-purpose terminal block for the SCXI-1127 or SCXI-1128 multiplexer/matrix switch modules. This terminal block offers 64 generic screw terminals for connection to the SCXI-1127/1128 lines and a cold-junction compensation sensor. Choose the SCXI-1331 when using the SCXI-1127 or SCXI-1128 to scan thermocouple or voltage signals or when you require a matrix configuration other than 8 columns X 4 rows.

The SCXI-1333 configures the SCXI-1129 high-density matrix as quad 4×16 (2-wire) matrix. This terminal block offers direct connectivity of signal wires to the screw terminals inside the terminal blocks. The terminal block works with the use of matrix expansion plugs for instant row expansion via column connection and requires no external wiring. The SCXI-1334 configures the SCXI-1129 high-density matrix as 4×64 (2-wire) matrix. It provides direct connectivity of signal wires to the screw terminals inside the terminal blocks. The terminal block works with the use of matrix expansion plugs and matrix expansion cables for instant row expansion and column expansion and requires no external wiring.

 

 

The SCXI-1335 configures the SCXI-1129 high-density matrix as quad 8×32 (2-wire) matrix. It provides direct connectivity of signal wires to the screw terminals inside the terminal blocks. The terminal block works with the use of matrix expansion plugs for instant row expansion via column connection and requires no external wiring. The SCXI-1336 configures the SCXI-1129 high-density matrix as a 16×16 (2-wire) matrix. It provides direct connectivity of signal wires to the screw terminals inside the terminal blocks. The terminal block also works with the use of the matrix expansion cable for instant row expansion and requires no external wiring. The SCXI-1337 configures the SCXI-1129 high-density matrix as a dual 8×16 (2-wire) matrix. It provides direct connectivity of signal wires to the screw terminals inside the terminal blocks. The terminal block also works with the use of the matrix expansion cable for instant row expansion and requires no external wiring.

The SCXI-1338 is a current input terminal block for the following analog input modules: the SCXI-1120, SCXI-1120D, SCXI-1125, and SCXI-1126. Every input contains a 249 Ohm precision resistor, so you can read 0-20 mA or 4-20 mA current inputs. The SCXI-1339 configures the SCXI-1129 high-density matrix as a dual 4×32 (2-wire) matrix. It provides direct connectivity of signal wires to the screw terminals inside the terminal blocks. The terminal block also works with the use of the matrix expansion cable for instant row expansion and requires no external wiring.

The SCXI-1381K is a kit of unassembled terminal block components for developers building custom SCXI terminal blocks with custom circuit boards and signal connectors. The SCXI-1381K includes metal terminal block housing, strain relief assembly, and 96-pin DIN connector for mating with SCXI modules. Designed for special OEM products, the kit does not include a circuit board or screw terminals for signal connections.

Stay tuned for part 8 in our SCXI blog series coming soon!