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.
2| ni.com | NI SCB-100 Installation Guide and Specifications

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.
4| ni.com | NI SCB-100 Installation Guide and Specifications

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.
6| ni.com | NI SCB-100 Installation Guide and Specifications

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;
8| ni.com | NI SCB-100 Installation Guide and Specifications

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.
10 | ni.com | NI SCB-100 Installation Guide and Specifications

Optional Input Filtering and Broken Thermocouple
Detection
To reduce noise, you can build a simple RC lowpass filter in the breadboard area.
Build broken-thermocouple-detection circuitry by connecting a high-value resistor between
the positive input and +5 V. The value of this resistor is relatively unimportant; a few
megaohms or more works fine. You can detect an open or defective thermocouple with a high-
value resistor. If the thermocouple opens, the voltage measured across the input terminals rises
to +5 V, a value much larger than any legitimate thermocouple voltage.
Sources of Error
When making thermocouple measurements with the SCB-100 and a MIO DAQ device, the
possible sources of error are compensation, linearization, measurement, and thermocouple
wire errors.
• Compensation error can arise from two sources—inaccuracy of the temperature sensor
and temperature differences between the sensor and the screw terminals. The sensor on
the SCB-100 board is specified to be accurate to ±0.5 °C. Minimize temperature
differences between the sensor and the screw terminals by keeping the SCB-100 board
away from drafts, heaters, and warm equipment.
• Linearization error is a consequence of the polynomials being approximations of the true
thermocouple output. The linearization error depends upon the degree of polynomial
used.
• Measurement error is the result of inaccuracies in the MIO DAQ device, including gain
and offset. If the MIO DAQ device is properly calibrated, the offset error should be zero.
The only remaining error is a gain error of ±0.08% of full range (refer to the DAQ device
specifications). If the input range is ±10 V and the gain is 500, gain error contributes
0.0008 by 20 mV, or 16 μV of error. If the Seebeck coefficient of a thermocouple is
32 μV/°C, this measurement error adds 0.5 °C of uncertainty to the measurement. For
best results, use a well-calibrated MIO DAQ device so that offsets can be ignored.
Eliminate offset error by grounding one channel on the SCB-100 board and measuring
the voltage. This value, the offset of the MIO DAQ device, then can be subtracted by
software from all other readings.
• Thermocouple wire error is the result of inconsistencies in the thermocouple
manufacturing process. These inconsistencies, or nonhomogeneities, are the result of
defects or impurities in the thermocouple wire. The errors vary widely depending on the
thermocouple type and even the gauge of wire used, but a value of ±2 °C is typical.
For best results, use an average of at least 100 readings to reduce the effects of noise.
NI SCB-100 Installation Guide and Specifications | © National Instruments | 11

Removing the Board
You can remove the board from the enclosure to solder components into place. To remove the
board, 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.
3. Open the top cover.
4. Loosen the strain-relief screws with a Phillips #2 screwdriver.
5. Remove the signal wires from the screw terminals.
6. Remove the board mount screws and 100-pin connector screws.
7. Tilt the board up and pull it out of the enclosure.
Soldering, Desoldering, and Cutting Via Traces
on the SCB-100 Board
The applications discussed here require you to make modifications to the printed circuit board,
usually in the form of adding components or cutting jumpers. Use a low-wattage soldering
iron (20 to 30 W) when soldering to the board.
To desolder on the SCB-100, vacuum-type tools work best. Use care when desoldering to
avoid damaging component pads.
Use only rosin-core, electronic-grade solder. Acid-core solder damages the printed circuit
board and components.
For each screw terminal, there are one or two vias next to the silkscreen showing the screw
terminal number, as shown in the SCB-100 Board Parts Locator Diagram, number 8. The vias
are shorted to the screw terminal so you can solder a component to the via to connect it to the
screw terminal signal.
The trace between each pair of vias can be cut if needed.
NI SCB-100 Specifications
The following specifications are typical at 25 °C, unless otherwise noted.
12 | ni.com | NI SCB-100 Installation Guide and Specifications

General
Number of screw terminals 101 (includes one no connect); all I/O signals
are available at screw terminals
Cold-junction sensor
Accuracy .±0.5 °C
Output .10 mV/°C
Caution Do not connect hazardous voltages (≥42 Vpk/60 VDC).
Power Requirement
Power consumption (at +5 VDC ±5%),
typical
10 mA with no signal conditioning installed
Note Limit the current drawn from the host computer's +5 VDC to about 800 mA,
maximum.
Physical Characteristics
Dimensional drawings are available on the SCB-100 product page.
Box dimensions 17.93 cm × 15.37 cm × 4.50 cm (7.06 in. ×
6.05 in. × 1.77 in.)
Weight 897 g (1 lb 15.6 oz)
I/O connectors One 100-pin female 0.050 series shielded D-
type connector
Screw terminals 101, including one No Connect (NC)
Wire gauge 14-26 AWG
Environmental
Operating temperature 0 to 70 °C
Storage temperature -55 to 125 °C
Relative humidity 5 to 90% noncondensing
Maximum altitude 2,000 m
Pollution Degree (indoor use only) 2
Waste Electrical and Electronic Equipment (WEEE)
EU Customers This symbol indicates that waste products should be disposed of
separately from municipal household waste according to
NI SCB-100 Installation Guide and Specifications | © National Instruments | 13

WEEE Directive 2002/96/EC of the European Parliament and the Council on waste
electrical and electronic equipment (WEEE). All products at the end of their life
cycle must be sent to a WEEE collection and recycling center. Proper WEEE
disposal reduces environmental impact and the risk to human health due to
potentially hazardous substances used in such equipment. Your cooperation in
proper WEEE disposal will contribute to the effective usage of natural resources.
For information about the available collection and recycling scheme in a particular
country, go to ni.com/environment/weee.
Refer to the NI Trademarks and Logo Guidelines at ni.com/trademarks for information on National Instruments
trademarks. Other product and company names mentioned herein are trademarks or trade names of their respective
companies. For patents covering National Instruments products/technology, refer to the appropriate location: Help»
Patents in your software, the patents.txt file on your media, or the National Instruments Patent Notice at ni.com/
patents. You can find information about end-user license agreements (EULAs) and third-party legal notices in the
readme file for your NI product. Refer to the Export Compliance Information at ni.com/legal/export-compliance for
the National Instruments global trade compliance policy and how to obtain relevant HTS codes, ECCNs, and other
import/export data. NI MAKES NO EXPRESS OR IMPLIED WARRANTIES AS TO THE ACCURACY OF THE
INFORMATION CONTAINED HEREIN AND SHALL NOT BE LIABLE FOR ANY ERRORS. U.S. Government
Customers: The data contained in this manual was developed at private expense and is subject to the applicable limited
rights and restricted data rights as set forth in FAR 52.227-14, DFAR 252.227-7014, and DFAR 252.227-7015.
© 2015 National Instruments. All rights reserved.
371224C-01 July 31, 2019