NI SCXI-1000 SCXI Chassis User Manual

NI SCXI-1000 Корпус SCXI Руководство пользователя

The SCXI Chassis User Manual is one piece of the documentation set for the data acquisition and SCXI system. You could have any of several types of documents, depending on the hardware and software in the system. Use the documents you have as follows: 

 • The SCXI Quick Start Guide—This document describes how to set up an SCXI chassis, install SCXI modules and terminal blocks, and configure the SCXI system in Measurement & Automation Explorer (MAX). 

 • The SCXI hardware user manuals—Read these manuals next for detailed information about signal connections and module configuration. They also explain in greater detail how the module works and contain application hints. 

 • The DAQ hardware user manuals—These manuals have detailed information about the DAQ hardware that plugs into or is connected to the computer. Use these manuals for hardware installation and configuration instructions, specification information about the DAQ hardware, and application hints. 

 • Software documentation—Examples of software documentation you may have are the LabVIEW, Measurement Studio, and NI-DAQ documentation sets. After you set up the hardware system, use either the application software (LabVIEW or Measurement Studio) or the NI-DAQ documentation to help you write your application. If you have a large, complicated system, it is worthwhile to look through the software documentation before you configure the hardware. 

 • Accessory installation guides or manuals—If you are using accessory products, read the terminal block and cable assembly installation guides or accessory user manuals. They explain how to physically connect the relevant pieces of the system. Consult these guides when you are making the connections. 

 • If you are designing your own module, the SCXIbus System Specification is available from NI upon request. This specification describes the physical, electrical, and timing requirements for the SCXIbus.

Optional Equipment

NI provides a full line of modules that amplify, filter, isolate, and multiplex a wide variety of signal types, such as thermocouples, resistance temperature detectors (RTDs), strain gauges, high-voltage inputs, current inputs, analog outputs, and digital I/O signals. Cables and terminal blocks with screw terminals, BNC connectors, or thermocouple plugs are available to connect signals to the modules. Refer to the latest NI catalog and ni.com/catalog for a complete listing of sensors and I/O types supported in SCXI

Configuring and Installing the SCXI Chassis

NI provides a full line of modules that amplify, filter, isolate, and multiplex a wide variety of signal types, such as thermocouples, resistance temperature detectors (RTDs), strain gauges, high-voltage inputs, current inputs, analog outputs, and digital I/O signals. Cables and terminal blocks with screw terminals, BNC connectors, or thermocouple plugs are available to connect signals to the modules. Refer to the latest NI catalog and ni.com/catalog for a complete listing of sensors and I/O types supported in SCXI.

Configuring and Installing the SCXI Chassis

This chapter contains instructions for configuring and installing the SCXI chassis. It describes the following: 

 • Chassis address selection 

 • Voltage and fuse selection 

 • Chassis, modules, and accessories installation 

 • Fan filter maintenance

Configuring the SCXI Chassis

Configuring the chassis involves selecting a chassis or high-level data link control (HDLC) address, line voltage, and fuse value on any chassis. Note Refer to the Read Me First: Safety and Radio-Frequency Interference document before removing equipment covers or connecting or disconnecting any signal wires.

Selecting Chassis Addresses 

These sections provide information about how to select addresses for the SCXI chassis.

SCXI-1000/1001

Unless you are using multiple chassis and need to configure one or more SCXI chassis for a different address, you can skip this section, and the SCXI chassis retains factory-default address of 0. You can configure the SCXI chassis for one of 32 different addresses so that you can connect multiple SCXI chassis to the same control source. The five switches on the front panel of Slot 0 determine the chassis address. Switches one through five represent the values 1, 2, 4, 8, and 16, when set to the ON position. When set to the OFF position, their value is zero. The chassis address is the sum of the switch values. Figure 2-7 shows examples of both the factory-default setting of the chassis address 0 and the switch setting for chassis address 19

Notes SCXI-1000 chassis through revision D do not have address jumpers or switches and respond to any address, but you cannot use them in multichassis systems. Revision E chassis use jumpers on Slot 0 for chassis addressing. Revision F and later chassis use a DIP switch for chassis addressing. SCXI-1001 chassis through revision D use jumpers on Slot 0 for chassis addressing. Revision E and later chassis use a DIP switch for chassis addressing.

SCXI-1000DC

Unless you are using multiple chassis and need to configure one or more SCXI chassis for a different address, you can skip this section, and the SCXI chassis retains the factory-default address of 0. You can configure the SCXI chassis for one of 32 different addresses so that you can connect multiple SCXI chassis to the same control source. Three jumpers that determine the chassis address are located behind the front panel of Slot 0 just below the Reset button. The chassis address is the sum of the values of all the jumpers. Figure 2-8 shows examples of both the factory-default setting of address 0 and the jumper settings for address 19

Note SCXI-1000DC chassis through revision C do not have address jumpers or switches and respond to any address, but you cannot use them in multichassis systems. Revision D and later chassis use jumpers on Slot 0 for chassis addressing.

Changing the Chassis Address 

 While referring to Figures 2-2 and 2-6, complete the following steps to change the chassis address of the SCXI-1000DC: 

 1. Power off the chassis and remove the power cord from the power entry module.

 2. To prevent a shock hazard, wait at least one minute before proceeding to step 3. 

 3. Using a screwdriver, remove the four (six on some revisions) panhead screws from the front panel of Slot 0. 

 4. Remove the six screws from the rear panel. 

 5. Remove the controller from Slot 0. 

 6. Set all three jumpers for the chassis address you want. 

 7. Replace the controller in Slot 0. 

 8. Replace the four (six on some revisions) screws. Do not overtighten.

 9. Replace the six screws in the rear panel. Do not overtighten

Selecting Voltage and Replacing the Fuse for the SCXI-1000 and SCXI-1001

If you ordered the chassis with the appropriate part number (the -0x extension of the kit part number corresponds to your geographical region), the voltage tumbler and fuse are correct for operation in your geographical region. Check the voltage on the voltage tumbler to ensure that you have the correct voltage tumbler setting and fuse. The SCXI chassis can operate with line voltages of 100, 120, 220, and 240 VAC. The voltage tumbler in the power entry module determines the voltage for which the chassis is configured. You can identify the operating voltage by looking at the number on the power entry module when the door that covers the tumbler is closed. The fuse is 5 × 20 mm, which has a current rating relative to the operating voltage. Table 2-4 shows the proper voltage selections and fuse ratings for different regions.

Selecting the Voltage

Complete the following steps to select a voltage: 

 1. Power off the chassis. 

 2. Remove the power cord from the power entry module. 

 3. Using a flathead screwdriver, pry the door to the tumbler open from thetop. 

 4. Remove the voltage tumbler. 

 5. Rotate the tumbler to the appropriate voltage and reinsert it into the power entry module. 

 6. Close the door. 

 7. Check to make sure that the voltage showing on the selection tumbler is correct. 

 8. Reinsert the power cord.

Replacing the Power Entry Module Fuse

Caution Disconnect all power before removing the cover. Complete the following steps to replace the power entry module fuse: 

 1. Power off the chassis. 

 2. Remove the power cord from the power entry module. 

 3. Using a flathead screwdriver, pry the door to the voltage selection tumbler open from the top. 

 4. Pull out the fuse drawer. 

 5. Remove the fuse. 

 6. Install the new fuse in the drawer. 

 7. Reinsert the fuse drawer in the right-hand slot with the arrow pointing to the right. 

 8. Close the door. 

 9. Reinsert the power cord.

Replacing and Checking Backplane Fuses on the SCXI-1000 and SCXI-1001

In addition to the power entry module fuse, the analog supply lines on the backplane are fused at 1.5 A on the SCXI-1000 chassis and at 4 A on the SCXI-1001 chassis. If you are making your own modules, fuse the module at 250 mA to avoid blowing the backplane fuses. Fusing the module better protects the module when a failure results in a large amount of current drawn by not allowing the current to blow the backplane fuses. On the SCXI-1000, the backplane fuses are located behind the fan. On the SCXI-1001, the backplane fuses are located behind the right-hand fan, near the power entry module, as viewed from the rear of the chassis.

Complete the following steps to check or replace fuses: 

 1. Remove the appropriate fan and filter from the rear of the chassis by following the instructions in the Maintaining the Fan Filter section. Make sure to switch the power off and remove the power cord.

2. The fuse marked with a copper + on the backplane is for the positive analog supply, and the fuse marked with a copper – is for the negative analog supply. To check whether a fuse is blown, connect an ohmmeter across the leads. If the reading is not approximately 0 Ω, replace the fuse.

3. Using a pair of needle-nose pliers, carefully extract the fuse.

4. Take a new fuse and bend its leads so the component is 12.7 mm (0.5 in.) long, the dimension between the fuse sockets, and clip the leads to a length of 6.4 mm (0.25 in.).

5. Using the needle-nose pliers, insert the fuse into the socket holes.

6. Repeat for the other fuse if necessary.

7. Check the fan filter and, if it is dirty, clean it as described in the Maintaining the Fan Filter section.

8. Reinstall the fan and filter

Replacing the Fuses on the SCXI-1000DC

There are two fuses located on the rear panel of the SCXI-1000DC. The input power fuse (F1) is a 6.3 A, 5 × 20 mm time-lag fuse. The internal +5 VDC supply is fused by a 3.15 A, 5 × 20 mm time-lag fuse (F2).

Replacing the Power Entry Fuse and +5 VDC Fuse

Caution For continued protection against fire, replace fuses only with fuses of the same type and rating.

Complete the following steps to replace the rear panel fuses: 

 1. Power off the chassis. 

 2. Remove the power cord from power entry connector J1. 

 3. Turn the fuse holder counter-clockwise with a screwdriver and pull out the fuse holder to expose the fuse in the housing. 

 4. Remove the fuse. 

 5. Install the new fuse. 

 6. Push the fuse holder back into the housing and screw it clockwise until it is secure. 

 7. Reinsert the power cord.

Replacing and Checking Backplane Fuses

In addition to the power entry and the +5 V supply fuses, the analog supply lines on the backplane are fused at 1.5 A on the SCXI-1000DC chassis. If you design a special/prototype module, use the SCXI-1181 module and fuse the module at 250 mA to avoid blowing the analog backplane and +5 V supply fuses. Fusing the module better protects the module when a failure results in a large amount of current drawn by not allowing the current to blow the backplane fuses and +5 V fuses. On the SCXI-1000DC, the backplane fuses are located behind the fan. Complete the following steps to check or replace fuses: 

 1. Remove the appropriate fan and filter from the rear of the chassis by following the instructions in the Maintaining the Fan Filter section. Be sure to switch the power off and remove the power cord. 

 2. The fuse marked with a copper + on the backplane is for the positive analog supply, and the fuse marked with a copper – is for the negative analog supply. To check whether a fuse is blown, connect an ohmmeter across the leads. If the reading is not approximately 0 Ω, replace the fuse. 

 3. Using a pair of needle-nose pliers, carefully extract the fuse. 

 4. Take a new fuse and bend its leads so the component is 12.7 mm (0.5 in.) long, the dimension between the fuse sockets, and clip the leads to a length of 6.4 mm (0.25 in.). 

 5. Using the needle-nose pliers, insert the fuse into the socket holes. 

 6. Repeat, if necessary, for the other fuse. 

 7. Check the fan filter and, if it is dirty, clean it as described in the Maintaining the Fan Filter section. 

 8. Reinstall the fan and filter.