National Instruments IMAQ SCB-100 User manual

INSTALLATION GUIDE AND SPECIFICATIONS
NI SCB-100
Shielded 100-Pin Connector Block for Plug-In DAQ Devices
This guide describes how to connect and use the NI SCB-100 with 100-pin data acquisition
(DAQ) devices.
The SCB-100 is a shielded desktop accessory with 100 screw terminals, a cold-junction
compensation temperature sensor for use with thermocouples, and a strain-relief bar for
securing signal wires or cables.
The SCB-100 connects to E Series MIO devices (NI 6025E, NI 6031E, NI 6033E, and NI
6071E), DIO devices (PCI-DIO-96, NI 6508, NI 6509, NI 6511, NI 6512, NI 6513, NI 6514,
NI 6515, NI 6527, and NI 6528), TIO Series devices (NI 6624), or other products with a 100-
pin 0.050 series shielded D-type I/O connector.
Note To use the SCB-100 with a DIO or TIO Series device, you must change the
default switch setting. Refer to the Using the SCB-100 with DIO/TIO Devices
section for more information.
The following illustration shows the SCB-100 components.

Figure 1. SCB-100 Connector Block
3
75
4
6
2
1
89
1. Quick Reference Label
2. Top Cover
3. 100-Pin Connector Screw
4. Grounding Screw
5. 100-Pin I/O Connector
6. Base
7. Strain-Relief Hardware
8. Strain-Relief Screws
9. SCB-100 Board Assembly
What You Need to Get Started
• SCB-100 100-pin shielded connector block and quick reference label
• 100-pin DAQ device and device documentation
• SH100100 cable (part number 182853-0x) for E Series/MIO devices or SH100-100-F
cable (part number 185095-0x) for DIO/TIO Series devices
• Phillips #1 and #2 screwdrivers
• 14-26 AWG wire
• Wire cutters
• Wire insulation strippers
• 1/8 in. flathead screwdriver
• Soldering iron and solder (optional)
• Long-nose pliers (optional)
• Resistors and capacitors specific to your application (optional)
Attaching the Quick Reference Label
A quick reference label is included in the SCB-100 100-pin shielded connector block kit to
show switch configurations and define screw terminal pinouts for E Series devices. Place the
label on the inside of the top cover.
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A PDF of the E Series quick reference label is available by going to ni.com/info and entering
the info code rdwpdf.
For DIO, TIO Series, or other 100-pin device signal information, refer to your device
documentation.
Getting Started with the SCB-100
Caution To avoid electrical shock, do not remove equipment covers or shields
unless you are qualified to do so. If signal wires are connected to the SCB-100,
hazardous voltages may exist even when the equipment is turned off. Before
removing the cover, disconnect the AC power or any live circuit from the connector
block.
The chassis ground terminals on your SCB-100 are for grounding high-impedance sources
such as a floating source (1 mA maximum). Do not use these terminals as safety earth
grounds.
Do not connect hazardous voltages (≥42 Vpk/60 VDC). National Instruments is not liable for
damage or injury resulting from such misuse.
The following figure shows the SCB-100 board parts locator diagram.
NI SCB-100 Installation Guide and Specifications | © National Instruments | 3

Figure 2. SCB-100 Board Parts Locator Diagram
2
4
6
6
1
3
5
9
6
3
7
8
3
3
1. Switches S4, S5, and S6
2. 100-Pin I/O Connector
3. Board Mount Screw Hole
4. Signal Accessory Power LED (DS1)
5. Switches S1, S2, and S3
6. Screw Terminals
7. Breadboard Area
8. Vias Shorted to Screw Termina
9. Cold-Junction Compensation Temperature Sensor
To get started with the SCB-100, complete the following steps.
1. Disconnect the 100-pin cable from the SCB-100, if connected.
2. Remove the grounding screws on either side of the top cover with a Phillips #1
screwdriver. Open the top cover.
3. Configure switches for the signal types you are using, as explained in the Using the
SCB-100 with DIO/TIO Devices section or the Using the SCB-100 with MIO Devices
section.
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4. Adjust the strain-relief hardware.
a. Loosen the strain-relief screws with a Phillips #2 screwdriver and slide the signal
wires through the front panel strain-relief opening.
b. If you are connecting multiple signals, remove the top strain-relief bar.
5. Add insulation or padding if necessary.
6. Connect the wires to the screw terminals by stripping 1/4 in. of insulation, inserting the
wires into the screw terminals, and tightening the screws.
7. Reinstall strain-relief (if removed) and tighten the strain-relief screws.
8. Close the top cover.
9. Reinsert the grounding screws to ensure proper shielding.
10. Connect the SCB-100 to the 100-pin connector.
Using the SCB-100 with DIO/TIO Devices
Caution Use the NI SH100-100-F cable with DIO devices, and the NI SH100-100
cable with MIO devices. Using the SH100-100 cable with a DIO device can damage
the device.
DIO devices, TIO Series devices, and DAQ devices without analog input functionality must
use the DIO/passthrough mode. Move the switches to the DIO/passthrough mode switch
setting as shown in the following table.
Table 1. DIO/TIO Series Device Switch Setting
Switch Setting Description
S6 S5 S4
S1
S2
S3
DIO/passthrough mode—Move switches S1, S2, S3, S4, S5, and
S6 to the positions shown on the left. In this mode:
• All 100 signals from the DAQ device connect directly to
screw terminals
• The signal accessory power LED (DS1) does not light in this
configuration.
Refer to the following figure for a detailed diagram.
NI SCB-100 Installation Guide and Specifications | © National Instruments | 5

Figure 3. DIO/Passthrough Mode Switch Setting
Temperature
Sensor
DAQ Device SH100-100-F Cable SCB-100 Screw
Terminal
100
99
1
100
99
1
2
2
NC
NC
NC
LED
S6 S5 S4
S1
S2
S3
Refer to your device documentation for device signal information.
Using the SCB-100 with MIO Devices
You can take measurements with the SCB-100 and MIO DAQ devices, such as E Series, in a
number of ways. The SCB-100 has a temperature sensor for cold-junction compensation to
accommodate thermocouples. Switches S4, S5, and S6 configure the temperature sensor for
different analog input settings. The following table shows the different switch settings for
MIO DAQ devices.
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Switch Setting Description
S6 S5 S4
S1
S2
S3
MIO with disabled temperature sensor mode (default
configuration)—Move switches S1, S2, S3, S4, S5, and S6 to the
positions shown on the left. In this mode:
• The temperature sensor is not used.
• AI 0 and AI 8 are available on screw terminals.
• The signal accessory power LED (DS1) lights when the
MIO device is powered on and connected to the SCB-100.
Refer to the following figure for a detailed diagram.
S6 S5 S4
S1
S2
S3
MIO with single-ended temperature sensor mode—Move
switches S1, S2, S3, S4, S5, and S6 to the positions shown on the
left. 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.
• The signal accessory power LED (DS1) lights when the
MIO device is powered on and connected to the SCB-100.
Refer to the following figure for a detailed diagram.
S6 S5 S4
S1
S2
S3
MIO with differential temperature sensor mode—Move switches
S1, S2, S3, S4, S5, and S6 to the positions shown on the left. In
this mode:
• The temperature sensor can be read using AI 0 and AI 8 in
differential mode.
• The signal accessory power LED (DS1) lights when the
MIO device is powered on and connected to the SCB-100.
Refer to the following figure for a detailed diagram.
S6 S5 S4
S1
S2
S3
DIO/passthrough mode—You can use DIO/passthrough mode
with an MIO device.
Refer to the Using the SCB-100 with DIO/TIO Devices section for
configuration information and a detailed diagram.
NI SCB-100 Installation Guide and Specifications | © National Instruments | 7

Figure 4. MIO Device Modes Switch Settings
Temperature
Sensor
DAQ Device SH100-100 Cable SCB-100
LED
S5
S4
Screw
Terminal
100
99
6
5
2
1
4
34
3
100
99
6
5
2
1
4
34
3
S6
S1
S2
S3
+5 V
AI 0
AI 8
Other
Pins
Refer to your device documentation for device signal information.
Temperature Sensor Output and Accuracy
The SCB-100 temperature sensor outputs 10 mV/°C and has an accuracy of ±0.5 °C.
You also can determine the temperature using the following formulas:
TC= 100 × Vt
TK=TC+ 273.15
TF=9
5×TC+ 32
Where
Vt is the temperature sensor output voltage;
TK is the temperature in Kelvin;
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TF and TC are the temperature readings in degrees Fahrenheit and degrees Celsius,
respectively.
Note Use the average of a large number of samples to obtain the most accurate
reading. Noisy environments require averaging more samples for greater accuracy.
Connecting Nonreferenced or Floating Signal
Sources to Analog Inputs
A floating signal source is a signal source that is not connected in any way to the building
ground system but has an isolated ground-reference point. If an instrument or device has an
isolated output, that instrument or device falls into the floating signal source category. Some
examples of floating signal sources are outputs for the following: thermocouples,
transformers, battery-powered devices, optical isolators, and isolation amplifiers. The ground
reference of a floating source must be tied to the ground of the MIO DAQ device to establish a
local or onboard reference for the signal. If this reference is not established, erratic readings
from the board will occur.
Differential Inputs
To provide a return path for the instrumentation amplifier bias currents, floating sources must
have a 10 to 100 kΩ resistor connected to the AI GND signal line on one input if DC-coupled,
or both inputs if AC-coupled. For detailed information on connections to floating signal
sources and differential inputs, refer to your device documentation.
Single-Ended Inputs
When measuring floating signal sources, configure the MIO DAQ device to supply a ground
reference. Therefore, configure the MIO DAQ device for referenced single-ended (RSE) input.
In this configuration, the negative input of the MIO DAQ device instrumentation amplifier is
tied to the analog ground. For detailed information on connections to floating signal sources
and single-ended inputs, refer to your device documentation.
Connecting Ground-Referenced Signal Sources
to Analog Inputs
A grounded signal source is connected in some way to the building system ground; therefore,
the signal source is already connected to a common ground point with respect to the MIO
DAQ device (assuming the host computer is plugged into the same power system).
Nonisolated outputs of instruments and devices that plug into the building power system fall
into this category.
NI SCB-100 Installation Guide and Specifications | © National Instruments | 9

Differential Inputs
If the MIO DAQ device is configured for differential inputs, ground-referenced signal sources
connected to the SCB-100 board do not require special components added to the SCB-100
board. For detailed information about connections to ground-referenced signal sources and
differential inputs, refer to your device documentation.
Single-Ended Inputs
The maximum voltage level generated by thermocouples is typically a few millivolts.
Therefore, for best resolution, use an MIO DAQ device with a high gain.
Thermocouples can be measured in either differential or single-ended configurations. The
differential configuration has better noise immunity, but the single-ended configuration has
twice as many inputs. The MIO DAQ device must have a ground reference because
thermocouples are floating signal sources. Therefore, you must install bias resistors if the MIO
DAQ device is in differential mode. For single-ended configuration, use the referenced single-
ended input configuration.
Cold-junction compensation with the SCB-100 is accurate only if the temperature sensor
reading is close to the actual temperature of the screw terminals. Therefore, when reading
thermocouples, keep the SCB-100 away from drafts or other temperature gradients such as
those caused by heaters, radiators, fans, and warm equipment.
Using the SCB-100 for Thermocouple
Measurements
The maximum voltage level generated by thermocouples is typically a few millivolts.
Therefore, for best resolution, use an MIO DAQ device with a high gain.
Thermocouples can be measured in either differential or single-ended configurations. The
differential configuration has better noise immunity, but the single-ended configuration has
twice as many inputs. The MIO DAQ device must have a ground reference because
thermocouples are floating signal sources. Therefore, you must install bias resistors if the MIO
DAQ device is in differential mode. For single-ended configuration, use the referenced single-
ended input configuration.
Cold-junction compensation with the SCB-100 is accurate only if the temperature sensor
reading is close to the actual temperature of the screw terminals. Therefore, when reading
thermocouples, keep the SCB-100 away from drafts or other temperature gradients such as
those caused by heaters, radiators, fans, and warm equipment.
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