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 National Instruments Corporation

5

SCXI-1321 Terminal Block Installation Guide

Figure 2.  

SCXI-1321 Circuit Parts Locator Diagram

Installing the Terminal Block

To connect the terminal block to the SCXI module front connector, 
complete the following steps:

1.

Connect the module front connector to its connector on the terminal 
block.

2.

Make sure that the module top and bottom thumbscrews do 

not

 

obstruct the rear panel of the terminal block.

3.

Tighten the top and bottom screws on the back of the terminal block to 
hold it securely in place.

4.

Refer to the 

Performed or Supported Signal Conditioning

 section for 

information on specific signal conditioning.

1

Screw Terminals

2

Product Information

3

W1 (CH0 Null Enabled)

4

W2 (CH1 Null Enabled)

5

R3 (CH0 Null Resistor)

6

R4 (CH0 Shunt Resistor)

7

R5 (CH1 Null Resistor)

8

R6 (CH1 Shunt Resistor)

9

R7 (CH2 Null Resistor)

10 R8 (CH2 Shunt Resistor)
11 R9 (CH3 Null Resistor)
12 R10 (CH3 Shunt Resistor)
13 W5 (CJC Mode)
14 Warning Label

15 W4 CH3 Null Enabled)
16 W3 (CH2 Null Enabled)
17 R15 (CH3 Null Potentiometer)
18 R14 (CH2 Null Potentiometer)
19 R2 (CH1 Null Potentiometer)
20 R1 (CH0 Null Potentiometer)

Note:

 R3 through R10 are socketed.

1

2

3

4

7

12

13

14

15

16

17

18

19

20

5

6

8

9

10

11

Содержание SCXI-1321

Страница 1: ...strain gauge shunt calibration This terminal block was primarily designed for Wheatstone bridge transducers such as strain gauges although it can easily accommodate thermocouples RTDs thermistors mill...

Страница 2: ...ames functions operations variables filenames and extensions and code excerpts monospace italic Italic text in this font denotes text that is a placeholder for a word or value that you must supply Wha...

Страница 3: ...is in current mode 4 Run the signal wires through the strain relief opening You can add insulation or padding if necessary 5 Prepare the signal wire by stripping the insulation no more than 7 mm 0 28...

Страница 4: ...stallation Guide 4 ni com Figure 1 SCXI 1321 Parts Locator Diagram 1 Strain Relief Bar 2 Strain Relief Screws 3 Safety Ground Lug 4 Mating Connector 5 Thumbscrew 6 Top Cover Screws 7 Top Cover Back Vi...

Страница 5: ...ock to hold it securely in place 4 Refer to the Performed or Supported Signal Conditioning section for information on specific signal conditioning 1 Screw Terminals 2 Product Information 3 W1 CH0 Null...

Страница 6: ...01 k 1 RNULL 39 k 5 RTRIM 10 k Nulling potentiometer Range 0 to 10 k Step size infinite user adjustable Mechanical Resistor sockets Connecting lead size 0 023 to 0 026 in Connecting lead length 0 110...

Страница 7: ...1010 1 EN 61010 1 UL 3111 1 UL61010B 1 CAN CSA C22 2 No 1010 1 Note For UL and other safety certifications refer to the product label or to ni com Electromagnetic Compatibility Emissions EN 55011 Clas...

Страница 8: ...and its own trimming potentiometer as listed in Table 1 To null the static offset voltage of the bridge complete the following steps 1 Connect the bridge configuration to the selected channel 2 Select...

Страница 9: ...ile referring to Figures 3 through 5 where Vexc is the excitation voltage 3 3 V or 10 V Rd is either a completion resistor or a second strain gauge nominal resistance Rnull is the nulling resistor val...

Страница 10: ...strain formula for a quarter bridge strain gauge configuration where Figure 3 Quarter Bridge Nulling Circuit 4Vr GF 1 2Vr Vr strained voltage static unstrained voltage Vexc CH CH CH EX EX R1 R2 4 5 k...

Страница 11: ...on Guide Figure 4 Half Bridge Nulling Circuit CH CH CH EX EX R1 R2 4 5 k 4 5 k RSCAL 301 k RTrim 10 k RNull 39 1 k Screw Adjusts Potentiometer RL RL RL R4 gauge EX CH CH CH EX EX RTrim SCXI 1121 SCXI...

Страница 12: ...L is engaged on a channel all the shunt switches of the channels are closed When SCAL is disengaged all the switches are open At startup or reset all switches are open by default You can control SCAL...

Страница 13: ...ur application The sockets and corresponding channels are shown in Table 3 The factory installed RSCAL provided on the terminal block have a 301 k 1 value Assuming a quarter bridge strain gauge config...

Страница 14: ...e number of samples to obtain the most accurate reading Noisy environments require averaging for greater accuracy You cannot use virtual channels to take the readings You can enable the CJC sensor in...

Страница 15: ...CH3 is not available RTD and Thermistor Excitation By properly setting the excitation you can configure the SCXI 1321 on a per channel basis for RTD and thermistor measurements With the SCXI 1121 exci...

Страница 16: ...ctory default setting Nulling circuit of Channel 2 is disabled W4 Nulling circuit of Channel 3 is enabled factory default setting Nulling circuit of Channel 3 is disabled Table 4 Jumper Settings of th...

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