Instruction/ maintenance manual of the product SCXI-1321 National Instruments
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SCXI-1321 T erminal Block Installation Guide 2 ni.com italic Italic text denotes variables, emphasis, a cross reference, or an int roduction to a key concept. This font also denote s te xt that is a placeholder for a word or v alue that you must supply .
© National Instruments Cor poration 3 SCXI-1321 T erminal Block Installa tion Guide Connecting the Signals Note Refer to the Read Me First: Safety and Radio-Frequency Interference document before removing equipment covers, or connecting or disconnecting any signal wires.
SCXI-1321 T erminal Block Installation Guide 4 ni.com Figure 1. SCXI-132 1 Parts Locator Diagram 1 Strain-Relief Bar 2 Strain-Relief Screws 3 Safety-Ground Lug 4 Mating Connector 5 Thumbscrew 6 Top-Co.
© National Instruments Cor poration 5 SCXI-1321 T erminal Block Installa tion Guide Figure 2. SCXI-1321 Circuit Parts Locator Diagram Installing the T erminal Block To connect the terminal block to the SCXI mo dule front connector, complete the follow ing steps: 1.
SCXI-1321 T erminal Block Installation Guide 6 ni.com Note T o minimize the temperature gradient inside the termin al block, move the SCXI chassis aw ay from any extr eme temperature dif ferential. Specifications All specifications are typical at 25 °C unless otherwise specified .
© National Instruments Cor poration 7 SCXI-1321 T erminal Block Installa tion Guide Environmental Operating temperature........................ .... 0 to 50 °C Storage temperature ............. ................. . –20 to 70 °C Humidity ..........
SCXI-1321 T erminal Block Installation Guide 8 ni.com Note Refer to the Declaration of Conformity (DoC) for this product fo r any additional regulatory compliance in formation. T o obtain th e DoC for this p roduct, click Declarations of Conformity Information at ni.
© National Instruments Cor poration 9 SCXI-1321 T erminal Block Installa tion Guide The factory default v alue of all the nulling resistors on the terminal blo ck is 39 k Ω . Note These resistors are socketed for easy re placement. These sockets best f it a 1/4 W resistor lead size.
SCXI-1321 T erminal Block Installation Guide 10 ni.com Assuming a strain-gauge range with a gauge factor of GF = 2 and a quarter-bridge conf iguration, this range corresponds to ±1,498 µε , as given by the strain formula for a quarter-bridge strain-gauge configuration: where Figure 3.
© National Instruments Cor poration 11 SCXI-1321 T erminal Bloc k Installa tion Guide Figure 4. Half-Bridge Nulling Circuit CH+ CH+ CH– EX+ EX– + – + – R 1 R 2 4.
SCXI-1321 T erminal Block Installation Guide 12 ni.com Figure 5. Full-Bridge Nulling Cir cuit Shunt Calibration Shunt calibration prov ides a method of adjusti ng for gain error to improve accuracy.
© National Instruments Cor poration 13 SCXI-1321 T erminal Bloc k Installa tion Guide z is the module slot of the SCXI-1121 w is the channel o f the module that you want to engage th e shunt and take.
SCXI-1321 T erminal Block Installation Guide 14 ni.com gauge with a gauge factor of GF = 2, V exc = 3.3 V , and R = 120 Ω prod uces the following: V change = 0.3321 mV Replacing the strained voltage by V change in the quarter-bridge strain equation produces an equ i valent 199 µε of change.
© National Instruments Cor poration 15 SCXI-1321 T erminal Bloc k Installa tion Guide Y ou can read a temperature at the begi nning of the test and use that value with the data that follows. Using this method assumes that there are no temperature v ariations during the measurement period.
321924C-01 J an03 *321924C-01* W3 Nulling circuit of Channel 2 is enabled (factory 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.
An important point after buying a device National Instruments SCXI-1321 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought National Instruments SCXI-1321 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data National Instruments SCXI-1321 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, National Instruments SCXI-1321 you will learn all the available features of the product, as well as information on its operation. The information that you get National Instruments SCXI-1321 will certainly help you make a decision on the purchase.
If you already are a holder of National Instruments SCXI-1321, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime National Instruments SCXI-1321.
However, one of the most important roles played by the user manual is to help in solving problems with National Instruments SCXI-1321. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device National Instruments SCXI-1321 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
