NI SCXI-1000 SCXI Chassis User Manual

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.