National Instruments SCB-68 User manual

SCB-68 Getting
Started
2022-07-06

Contents
SCB-68 UG Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
What You Need to Get Started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Getting Started with the SCB-68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Using the SCB-68 in Direct Feedthrough Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Using the SCB-68 with Multifunction I/O Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Connecting Signal Sources to Analog Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Fuse and Power Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Where to Go from Here. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
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SCB-68 Getting Started

SCB-68 UG Introduction
This guide describes how to connect and use the SCB-68 with 68-pin or 100-pin data
acquisition (DAQ) devices and other NI products with a 68-pin SCSI or VHDCI I/O
connector. For a complete list of supported devices and available SCB-68 features,
visit ni.com/r/scb68dev.
Note To use the SCB-68 with devices without analog input functionality,
you must change the default switch setting. Refer to Using the SCB-68 in
Direct Feedthrough Mode for more information.
Figure 1. SCB-68 Parts Locator Diagram
3
8
9
1 2
5
6
7
10
8
5
4
1. Quick Reference Label (Optional)
2. Top Cover
3. 68-Pin Connector Screws
4. Lock Washers
5. Shielding Screws
6. 68-Pin I/O Connector
7. Base
8. Strain-Relief Screws
9. Strain-Relief Hardware
10. SCB-68 Board Assembly
© National Instruments 3
SCB-68 Getting Started

What You Need to Get Started
To set up and use your SCB-68, you need the following:
■SCB-68 68-pin shielded connector block kit(s)[1]
■Compatible 68-pin or 100-pin DAQ device, and device documentation
■The correct cable(s) for your device, as listed at ni.com/r/scb68dev.
■Phillips #1 and #2 screwdrivers
■0.125 in. flathead screwdriver
■14–30 AWG wire
■Wire cutters
■Wire insulation stripper
1 You can use up to two SCB-68 accessories with supported products with two 68-
pin connectors or one 100-pin connector. You can use up to three SCB-68
accessories with supported products with three 68-pin connectors, and up to four
SCB-68 accessories with supported products with four 68-pin connectors.
Getting Started with the SCB-68
The following cautions contain important safety information concerning hazardous
voltages and connector blocks.
Caution To avoid electrical shock, do not remove equipment covers or
shields unless you are qualified to do so. Before removing the cover,
disconnect any live circuit from the connector block.
Caution The chassis ground terminals on your SCB-68 are for grounding
high-impedance sources, such as a floating source (1 mA maximum). Do
not use these terminals as safety earth grounds.
Caution Do not connect hazardous voltages (≥42 V pk/60 V DC).
The following figure shows the SCB-68 board parts locator diagram.
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SCB-68 Getting Started

Figure 2. SCB-68 Printed Circuit Board Diagram
1 2 43
5
6
36
SCB-68
©COPYRIGHT 1993
68
J1
34
12
46
13
47
14
48
15
49
16
50
17
51
18
52
19
53
20
54
21
55
22
56
1
35
2
36
3
37
4
38
5
39
6
7
41
8
42
9
43
10
44
11
45
67
33
66
32
65
31
64
30
63
29
62
28
61
27
60
26
59
25
58
24
57
23
C6
C5
C3
C1
C2
XF1
ASSY182470-01 REV.B S/N
1 3 33 34
C4
R20
R21
RC12(B) RC4(E)
R4(F)
S5 S1
S2
S4 S3
R5(G)
RC5(E)
R6(F)
R7(G)
RC13(D)
R22(A)
R23(C)
RC14(B)
RC15(D)
R24(A)
R25(C)
RC6(E)
R8(F)
R9(G)
RC16(B)
RC17(D)
R26(A)
R27(C)
RC7(E)
R10(F)
R11(G)
RC18(B)
RC19(D)
R28(A)
R29(C)
RC8(E)
R12(F)
R13(G)
RC20(B)
RC21(D)
R30(A)
R31(C)
RC9(E)
R14(F)
R15(G)
RC22(B)
RC23(D)
R32(A)
R33(C)
RC10(E)
R16(F)
R17(G)
RC24(B)
RC25(D)
R34(A)
R35(C)
RC11(E)
R18(F)
RC2
R2
RC3
R3
R19(G)
RC26(B)
RC27(D)
R36(A)
R37(C)
R38
R10
RC1
7
7
6 7
40
8
1. Switches S3, S4, and S5
2. 68-Pin I/O Connector
3. Breadboard Area
4. Fuse (800 mA, 250 V, 5 × 20 mm)
5. Switches S1 and S2
6. Screw Terminals
7. Signal Conditioning Areas
8. Temperature Sensor
To get started with the SCB-68, complete the following steps while referring to
Figures 1 and 2. If you have not already installed your DAQ device, refer to the DAQ
Getting Started Guide for instructions.
1. Disconnect the cable from the SCB-68, remove the shielding screws with a
Phillips #1 screwdriver, and open the top cover.
© National Instruments 5
SCB-68 Getting Started

2. Attach the quick reference label to the inside of the top cover as shown in
Figure 1. You can find quick reference labels, which specify accessory pinout
information for many compatible devices, by going to ni.com/r/scb68dev.
3. Configure switches for the signal types you are using, as explained in Using
the SCB-68 in Direct Feedthrough Mode or Using the SCB-68 with
Multifunction I/O Devices.
4. Adjust the strain-relief hardware by loosening the strain-relief screws with a
Phillips #2 screwdriver and sliding the signal wires through the front panel
strain-relief opening. If you are connecting multiple signals, remove the top
strain-relief bar and add insulation or padding if necessary.
5. Connect the wires to the screw terminals by stripping 6.35 mm (0.25 in.) of
insulation, inserting the wires into the screw terminals, and securely
tightening the screws with the flathead screwdriver to a torque of
0.5–0.6 N · m(4.43–5.31 lb · in.).
6. Reinstall the strain-relief (if removed) and tighten the strain-relief screws.
7. Close the top cover and reinsert the shielding screws to ensure proper
shielding.
Caution Do not connect input voltages ≥42 V pk/60 V DC to the
SCB-68. The SCB-68 is not designed for any input voltages ≥42 V pk/
60 V DC, even if a user-installed voltage divider reduces the voltage
to within the input range of the DAQ device. Input voltages ≥42 V pk/
60 V DC can damage the SCB-68, all devices connected to it, and the
host computer.
8. Connect the SCB-68(s) to the DAQ device using the appropriate cable(s) for
your device. For a complete list of cabling options for supported devices, visit
ni.com/r/scb68dev.
9. Launch Measurement & Automation Explorer (NI MAX), confirm that your DAQ
device is recognized, and configure your device settings. Refer to the DAQ
Getting Started Guide for more information.
10. (Optional) If you are going to take measurements with an MIO DAQ device,
configure the SCB-68 as an accessory for a DAQ device using MAX by
completing the following steps.
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SCB-68 Getting Started

1. In the le pane of MAX, expand Devices and Interfaces, then right-click
your DAQ device and select Properties from the pull-down menu.
2. Select the Accessory tab from the dialog box, select SCB-68 from the
pull-down menu, then select Configure.
For more information about configuring the SCB-68 for a DAQ device,
refer to the Measurement & Automation Explorer Help for NI-DAQmx.
11. Test specific device functionality. Refer to the DAQ Getting Started Guide for
detailed information about running test panels in MAX.
When you have finished using the SCB-68, power o any external signals connected
to the SCB-68 before you power o your computer.
Using the SCB-68 in Direct Feedthrough Mode
NI 25xx, NI 4309, NI 65xx, NI 66xx, NI 67xx, and NI 78xx, and products without
analog input functionality must use direct feedthrough mode. Move the switches to
the direct feedthrough mode switch setting shown in the following table.
Switch Setting Description
S5 S4 S3
S1
S2
Direct feedthrough mode—Move switches S1, S2, S3, S4, and S5 to the positions
shown at le. In this mode:
■All 68 signals from the device connect directly to screw terminals
Refer to the following figure for a detailed diagram.
Table 1. Direct Feedthrough Switch Setting
Figure 3. Direct Feedthrough Mode Switch Setting
Temperature
Sensor
Device Cable SCB-68 Screw
Terminal
68
67
1
68
67
1
2
2
NC
Refer to
Your Device
Documentation
for Device
Signal
Information
S5 S4 S3
S1
S2
Signal
Conditioning NC
© National Instruments 7
SCB-68 Getting Started

Using the SCB-68 with Multifunction I/O Devices
You can take measurements with the SCB-68 and multifunction I/O (MIO) DAQ
products, such as NI 60xx/61xx/62xx/63xx, in a number of ways. Switches S1 and S2
provide power to the signal conditioning area of the accessory. The SCB-68 has a
temperature sensor for cold-junction compensation (CJC) to accommodate
thermocouples; switches S3, S4, and S5 configure the temperature sensor for
dierent analog input settings. The following table shows the dierent switch
settings for MIO DAQ devices.
Switch Setting Description
S5 S4 S3
S1
S2
MIO with disabled temperature sensor mode (default configuration) *—Move
switches S1, S2, S3, S4, and S5 to the positions shown at le. In this mode:
■The temperature sensor is not used.
■AI 0 and AI 8 are available on screw terminals.
■+5 V power provided to signal conditioning area of the accessory.
Refer to the following figure for a detailed diagram.
S5 S4 S3
S1
S2
MIO with single-ended temperature sensor mode *,†—Move switches S1, S2, S3,
S4, and S5 to the positions shown at le. In this mode:
■The temperature sensor can be read using AI 0 in referenced single-
ended (RSE) mode.
■AI 8 is available on a screw terminal.
■+5 V power provided to signal conditioning area of the accessory.
Refer to the following figure for a detailed diagram.
S5 S4 S3
S1
S2
MIO with differential temperature sensor mode—Move switches S1, S2, S3, S4,
and S5 to the positions shown at le. In this mode:
■The temperature sensor can be read using AI 0 and AI 8 in dierential
mode.
■+5 V power provided to signal conditioning area of the accessory.
Refer to the following figure for a detailed diagram.
S5 S4 S3
S1
S2
Direct feedthrough mode—Move switches S1, S2, S3, S4, and S5 to the positions
shown at le. In this mode:
■All 68 signals from the device connect directly to screw terminals.
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SCB-68 Getting Started

Switch Setting Description
Refer to Using the SCB-68 in Direct Feedthrough Mode for a detailed diagram.
* Not available on Connectors 1, 2, 3 of NI 6225/6255 or NI 6345/6355/6365/6375 devices.
† Not available on NI 61xx devices.
Table 2. MIO DAQ Device Switch Settings
Figure 4. MIO Device Modes Switch Settings
Temperature
Sensor
MIO DAQ Device Cable SCB-68
S5
S4
Screw
Terminal
67
66
3
2
1
34
8
68
67
66
3
2
1
34
8
68
S3
S1
S2
+5 V
AI 0
AI 8
Other
Pins
Refer to
Your Device
Documentation
for Device
Signal
Information
Signal
Conditioning
Connecting Signal Sources to Analog Inputs
For detailed information about connections from floating or ground-referenced
signal sources to analog inputs, refer to your device documentation.
Refer to the SCB-68 User Manual for Advanced Functions for more information
about using the temperature sensor, taking thermocouple measurements, and
adding bias resistors and signal conditioning components to the SCB-68.
Fuse and Power Information
Some DAQ devices provide +5 V power on pin 8 and pin 14. Pin 8 from the DAQ
device is protected by an 800 mA, 250 V, 5 × 20 mm fuse on the SCB-68, shown in
Figure 2. Shorting pin 8 to ground blows the fuse on the SCB-68. Pin 14 is not fuse-
© National Instruments 9
SCB-68 Getting Started

protected on the SCB-68. Shorting pin 14 will cause the fuse on the DAQ device to
open.
If the SCB-68 does not work when you power on the DAQ device, check the switch
settings, then check the fuse on the SCB-68, shown in Figure 2, and the output fuse
(if any) on the DAQ device. Littelfuse part number 235.800 (www.littelfuse.com) is a
suitable replacement fuse. Before replacing any fuses, check for short circuits from
power to ground.
Refer to the SCB-68 User Manual for Advanced Functions for information about
filtering the power on the SCB-68.
Where to Go from Here
Refer to the SCB-68 User Manual for Advanced Functions, available from ni.com/
manuals, for information about the temperature sensor, thermocouple
measurements, bias resistors, soldering components on the SCB-68, filtering,
current input measurements, and accessory specifications.
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SCB-68 Getting Started
© 2022 National Instruments Corporation.