Measurement Computing IOtech 6224 User manual

USER’S MANUAL
6224
Measurement Computing
10 Commerce Way
Norton, MA 02766
[phone]
Fax: [phone]
[email protected]
www.mccdaq.com
High-speed, Strain Gauge Input Module
12 Channel 24-Bit Half/Full-Bridge Analog Input Ethernet
*372738C-01*
372738C-01 Rev 1.2

Warranty Information
Contact Measurement Computing by phone, fax, or e-mail in regard to warranty-related issues:
Phone: [phone], fax: [phone], e-mail: [email protected]
Limitation of Liability
Measurement Computing cannot be held liable for any damages resulting from the use or misuse of this product.
Copyright, Trademark, and Licensing Notice
All Measurement Computing documentation, software, and hardware are copyright with all rights reserved. No part of
this product may be copied, reproduced or transmitted by any mechanical, photographic, electronic, or other method
without Measurement Computing’s prior written consent. IOtech product names are trademarked; other product names, as
applicable, are trademarks of their respective holders. All supplied IOtech software (including miscellaneous support
files, drivers, and sample programs) may only be used on one installation. You may make archival backup copies.
CE Notice
Many Measurement Computing products carry the CE marker indicating they comply with the safety and emissions
standards of the European Community. When applicable these products have a Declaration of Conformity stating which
specifications and operating conditions apply. You can view the Declarations of Conformity at
www.mccdaq.com/legal.aspx (CE Information page).
Warnings, Cautions, Notes, and Tips
Refer all service to qualified personnel. This caution symbol warns of possible personal injury or equipment damage
under noted conditions. Follow all safety standards of professional practice and the recommendations in this manual.
Using this equipment in ways other than described in this manual can present serious safety hazards or cause equipment
damage.
This warning symbol is used in this manual or on the equipment to warn of possible injury or death from electrical
shock under noted conditions.
This ESD caution symbol urges proper handling of equipment or components sensitive to damage from electrostatic
discharge. Proper handling guidelines include the use of grounded anti-static mats and wrist straps, ESD-protective bags
and cartons, and related procedures.
This symbol indicates the message is important, but is not of a Warning or Caution category. These notes can be of great
benefit to the user, and should be read.
In this manual, the book symbol always precedes the words “Reference Note.” This type of note identifies the location
of additional information that may prove helpful. References may be made to other chapters or other documentation.
Tips provide advice that may save time during a procedure, or help to clarify an issue. Tips may include additional
reference.
Specifications and Calibration
Specifications are subject to change without notice. Significant changes will be addressed in an addendum or revision to
the manual. As applicable, the hardware is calibrated to published specifications. Periodic hardware calibration is not
covered under the warranty and must be performed by qualified personnel as specified in this manual. Improper
calibration procedures may void the warranty.

CAUTION
Using this equipment in ways other than described in this manual can cause
personal injury or equipment damage. Before setting up and using your
equipment, you should read all documentation that covers your system.
Pay special attention to Warnings and Cautions.
Note:
During software installation, Adobe®PDF versions of user manuals will automatically
install onto your hard drive as a part of product support. The default location is in the
Programs group, which can be accessed from the Windows Desktop. Initial navigation
is as follows:
Start [on Desktop] All Programs IOtech …
Refer to the PDF documentation for information regarding hardware and software.
For detailed information regarding Encore software, refer to the Help information that
can be accessed directly from IOtech’s Encore application following its installation.

6224 User’s Manual vii
Table of Contents
F
Quick Start
Chapter 1 –General Information
Introduction …. 1-1
Front Panel …… 1-1
Rear Panel …… 1-2
Analog Circuitry …… 1-31
Synchronization …… 1-4
Stacking Plate and Handle Options …… 1-5
Quarter-Bridge Accessories(CN-269 & CN-270) …… 1-6
RJ50 12-Pin Screw Terminal Accessory (CN-268) …… 1-7
RJ50 Cables (CA-272-01) …… 1-7
Chapter 2 –Block Diagram
Chapter 3 –Pinouts and Connections
Strain Channels, RJ50 Pinout …… 3-1
Half-Bridge and Full-Bridge Connections …… 3-2
Connecting TEDS Channels…… 3-2
Remote Sensing …… 3-2
Shunt Calibration …… 3-3
Internal Excitation Voltage Sources …… 3-3
External Excitation Voltage Sources …… 3-4
Mounting and Securing Connections …… 3-5
Where to Find Additional Information …… 3-5
Chapter 4 –Counter Input
Counter Settings …… 4-1
Encoder Settings …… 4-2
Chapter 5 –CE Compliance and Noise Considerations
Overview …… 5-1
CE Standards and Directives …… 5-1
Safety Conditions …… 5-2
Emissions/Immunity Conditions …… 5-3
CE Rules of Thumb …… 5-3
Noise Considerations …… 5-4
Chapter 6 –Software, IOtech Encore
Chapter 7 –Strain and Pressure Force
Chapter 8 –Product Care and Customer Support
Electrostatic Discharge (ESD), Handling Notice…… 8-1
Product Care …… 8-1
The Readme Files and the Install CD-ROM …… 8-2
Customer Support …… 8-2
Chapter 9 –Specifications, IOtech 6224
1For information regarding digital circuitry, refer to the Digital I/O section of the Specifications chapter.

Rev 1.2 325130C-01
IOtech 6224 Quick Start
High-speed, Strain Gauge Input Module
Before you get started verify that you have the following items
and meet or exceed the minimum requirements listed.
IOtech 6224
TR-60U Power Supply and Cable
Ethernet Crossover Cable*
IOtech Encore Installation CD
PC: Minimum Requirements:
CPU: Intel®Pentium®4, 3.0 GHz or equivalent
RAM: 1 GB
Monitor: 1024 by 768 screen resolution
PC: Recommended:
CPU: Intel®CoreTM 2 Duo Family
RAM: 2+ GB
Monitor: 1024 by 768 screen resolution
Step 1 - Connect the 6224 to the Ethernet and to the Power Supply
In this scenario the 6224 is connected directly to an Ethernet port on a host computer.
1. Connect the Ethernet cable to the Ethernet jack on the 6224. If connecting directly to the PC, as indicated
above (i.e., instead of connecting to a network hub) you must use an Ethernet crossover cable.
2. Connect the other end of the Ethernet cable to the Ethernet jack on the host computer or network hub.
3. Connect the power supply cable from the TR-60U Power Supply to the External Power connector on the 6224.
4. Connect the TR-60U to a standard AC outlet; and set the rear panel Power Switch to “I” to turn the unit on.
The 6224 Power LED will light up.
5. If Encore software is already installed, reboot the PC and skip to Step 3; otherwise proceed to Step 2, Install
Encore Software.
Step 2 –Install Encore Software
1. Close all running applications on the host PC.
2. Insert the Encore CD into your CD-ROM drive and wait for the CD to auto-run.
An Opening Screen will appear. If AutoRun is disabled: (a) right-click Windows Start menu,
(b) select Explore, (c) navigate to the CD ROM drive, and (d) double-click Autorun.exe
3. Follow the screen prompts.
*An Ethernet crossover cable (provided) should only be used when connecting a 6000
Series device directly to the PC. A standard Ethernet cable should be used when
connecting via a hub/switch. A Gigabit switch is recommended when connecting
multiple devices.
IMPORTANT: You must use a crossover cable if
connecting a 6000 Series device directly to the PC.

Printed in Hungary
Step 3 –Use Encore to Configure the 6224
1. Run the Encore software application (Start>>All Programs>>IOtech>>Encore).
2. In Encore’s main toolbar, click the Hardware Configuration button. The Hardware Configuration window will open.
3. Select your device from the Detected Devices panel.
4. Click the top arrow button to set your device as a Project Device.
5. In Encore’s Hardware Configuration window, look in the Device Information panel to verify that your 6224 has an
IP Address. Note the following points regarding common connection scenarios. Both points assume that you have not
changed the 6224 from its default setting of Obtain an IP Address Automatically.
oDirect Connect –When a 6000 Series device is connected directly (via crossover cable or hub/switch) to a host PC
with no fixed IP Address, you will need to reboot the PC and the device to allow a default IP Address to be set. This
setting of an IP Address is automatic. No other action is needed. (See note.)
oNetwork Connect (Common scenario using existing network with DHCP server) –A 6000 Series device will
automatically request and receive an IP Address. No user action is needed. (See note.)
Note - Encore will provide a message to indicate an IP Address problem if one exists. If you receive such a message,
consult your network administrator and also check Encore’s Comprehensive Help file (via the Help pull-down menu on
Encore’s main window). Look at the topic: Connection Scenarios and IP Addresses (under Configuring Hardware
>>Hardware Setup).
6. Click the Next button (at the bottom of the Hardware Configuration dialog) to access the Acquisition Setup tab.
7. Configure and enable channels as desired for your application. For detailed information refer to Encore’s Comprehensive
Help file (via the Help pull-down menu on Encore’s main window).
Make sure that each computer and each device on the dedicated network has a unique IP address.
Step 4 - Connect Signal Lines
CAUTION
Turn off power to the system devices and externally connected equipment before connecting
cables. Electric shock or damage to equipment can result even under low-voltage conditions.
Take ESD precautions (packaging, proper handling, grounded wrist strap, etc.)
The 6224 uses 10-pin RJ50 jacks for strain connection. Do not connect RJ45 plugs to these
RJ50 jacks. Using RJ45 plugs can cause permanent damage to RJ50 pins 1 and 10, thus
disabling shunt calibration.
The 6224 has 12 analog channel inputs (CH1 through CH12) via front panel RJ50 jacks and 8 digital I/O lines via
rear panel DB9 connector.
Prior to making signal connections review the Specifications chapter of your 6224 user’s manual to ensure that the input
signals do not exceed the specified limits. After you have installed Encore you can access the pdf manual by navigating
from the host PC’s Windows Start Menu as follows (location shown is the default):
Start>>All Programs>>IOtech>>6000 Series>>6224 User Manual
Reference Note: The Encore software application includes Context-sensitive Help, Comprehensive Help,
a Quick Start Video Tutorial, and a Getting Started pdf.
Measurement Computing 10 Commerce Way, Norton, MA 02766
Phone: [phone], Fax: [phone] E-mail: i[email protected]
Internet: www.mccdaq.com
*325130C-01*
325130C-01

6224 User’s Manual General Information 1-1
General Information 1
Introduction …… 1-1
Front Panel …… 1-1
Rear Panel …… 1-2
Analog Circuitry1 …… 1-3
Synchronization …… 1-4
Stacking Plate and Handle Options ….. 1-5
Quarter-Bridge Completion Accessories(CN-269 & CN-270) …… 1-6
RJ50 12-Pin Screw Terminal Accessory (CN-268)….. 1-7
RJ50 Cables (CN-272-01) …… 1-7
Introduction
The 6224 is a twelve-channel, 24-bit resolution strain measurement device that connects to a host PC‟s Ethernet
port. The device is used to measure half-bridge and full-bridge sensors and can be synchronized with other 6000
series devices.
The hardware provides the signal conditioning and acquisition engine, while the software defines the specific
configuration and analysis aspects of the system.
Note that the software includes both a context sensitive Help and a comprehensive Help file.
6224 Basic profile:
Model
Interface
Analog
Input
Channels
SYNC
Ports
Analog
Output
Channels
Digital
I/O
TEDS
Support
Supported Bridges
(Note 3)
6224
10/100BaseT
Ethernet
12 Strain
RJ50 Jacks
2
0
1 port/
8 lines
(Note 2)
Quarter-Bridge I
Quarter-Bridge II
Half-Bridge I
Half-Bridge II
Full-Bridge I
Full-Bridge II
Full-Bridge III
Front Panel
The front panel houses twelve channel signal input jacks and
three excitation voltage source connectors, one for each set of
four channels.
The input channel jacks are type RJ50 (10p10c) and are labeled
CH1 through CH12. The 10-connector pinout for the RJ50
connectors is included in chapter 3.
Optional external voltage source connectors are available. For
additional information see the External Excitation Voltage
Sources section of chapter 3.
Do not connect an RJ45 plug to an RJ50 jack. Using RJ45 plugs can cause
permanent damage to RJ50 pins 1 and 10, thus disabling shunt calibration.
1For information regarding digital circuitry, refer to the Digital I/O section of the Specifications chapter.
2TEDS is supported by the 6224, but only if TEDS is supported by the software application.
3For information regarding the various bridge types, refer to chapter 7.

1-2 General Information 6224 User’s Manual
Rear Panel
The following items reside on the rear panel; from
left to right: 1st cable tie mount, Ethernet jack,
DB9-Digital I/O port, 2nd cable tie mount, #6-32
chassis ground screw, four status LEDs, two
synchronization jacks, a power input jack, and a
power switch. A description of each follows.
CABLE TIE MOUNTS: Two cable tie mounts are present to provide for strain relief of cables.
ETHERNET: The 10/100BaseT Ethernet port can connect to the Ethernet port of the host PC, or to an Ethernet
network. The Ethernet connector has two built in LEDs that indicate traffic flow on the network.
Refer to Accessories in the Specifications chapter for Ethernet cables available from Measurement Computing.
When connecting the unit directly to a PC (i.e., when not connecting to a network hub) you
will need to use an Ethernet crossover cable.
Ethernet cable length must be <3 m (9.8 ft) in order for the system to be CE Compliant.
DIGITAL I/O: Eight digital I/O lines are accessible via a 9-pin, female DSub connector. For details, refer to the
Digital I/O section of the Specifications chapter.
GROUND (#6-32): Provides a connection point for Chassis Ground via use of a #6-32 machine screw.
STATUS LEDS:
Power
„ON‟ when the device is connected to a sufficient power source and the power switch is
in the „l‟ (On) position.
Boot
During initial power up, the Boot light will be On to signal the first stage boot process.
When this has completed successfully, the Boot light will remain Off. If an internal
error is detected during this first stage boot process, this light will be blinking. Contact
Measurement Computing to arrange repair service.
Active
During initial power up, the Active light will be Off during the boot process, including
network configuration. The process will complete with a fast Blink, and then steady On
condition. With both the Power and Active lights On, the device is in the Ready state.
After this, the Active light will signal communications with a host computer at a slower
blink rate.
Data
The Data light will be On any time the device is acquiring channel data that is available
to the host PC control software.
Note:
After turning on the device, it can take up to 2 minutes to reach ready state, depending on
network settings. This can be monitored by the LED sequence:
Power Light On Boot Light On then Off Active Light Off, then Blinking, then On.
SYNC: Two “synchronization ports” provide a means of synchronizing units regard to pre-trigger data and post-
trigger scanning. Note that each 6000 Series device is capable of being designated as a Master Unit, Slave Unit, or
Terminating Slave Unit. The assignment is made in Encore. Refer to the following section, Synchronization, for
details. Refer to Accessories in the Specifications chapter for SYNC cables available from Measurement Computing.
Up to nine units can be synchronized. The total combined length of the SYNC cables is not
to exceed 2.438m (8 ft).
POWER INPUT: +19 VDC to +30 VDC, through a connector on the chassis. Power is typically supplied to the
device via a TR-60U, 24VDC universal power supply.
POWER SWITCH: A switch with a “0” label for Power Off, and a “ ” for Power On.

6224 User’s Manual General Information 1-3
Analog Circuitry
The 6224 is isolated from earth ground. However, the individual channels, within their four-channel group, are not
isolated from each other. The EX+, EX–, and T–signals are common among the four channels in their group as
indicated by note 1 on page 3-1 and in the block diagram (page 2-1).
You can connect the 6224 to a device that is biased at any voltage within the unit‟s rejection range of earth ground.
The Specifications chapter includes additional information.
Filtering
Passband -
Stopband -
Alias-Free Bandwidth -

1-4 General Information 6224 User’s Manual
Synchronization
To synchronize from two to nine 6000 Series devices, link
them together with synchronization cables as indicated in the
example figure. Note that the first device (relative to the
circuit) will be the Master. The last device connected will be
the Terminating Slave. Thus the synchronized devices must
proceed sequentially from the Master to Terminating Slave, as
indicated in the figures. Note that channel-to-channel phase
relationships in a multi-device configuration are not
necessarily fixed. See notes below.
After physically linking the devices via the sync cables, they must still be configured as a “Synchronized Device
Group” in the Encore software. To do this, use the Synchronize Devices page of Encore‟s Hardware Setup tab.
Each Synchronized Group consists of one Master Device
and at least one Slave Device. By default, the first 6000
Series device added to the Synchronization Group will be
the Master and the last device added to the group will be the
Terminating Slave.
Encore‟s Synchronized Device Group Configuration
panel includes a pull-down list which allows you to select
the device that you want to have function as Master and the
one you want to function as Terminating Slave, should this
be different than the default settings.
Encore will display a Synchronization Error icon if it
detects that a necessary synch cable is missing or not
properly connected.
Up to nine units can be synchronized. The total combined length of the SYNC cables is not
to exceed 2.438m (8 ft).
Unplug sync cables from devices that are not intended to be part of a “Synchronized Device
Group.” Leaving a sync cable connected to an independent device can lead to errors.
Leaving an un-terminated sync cable on a synchronized device can lead to errors.
The sampled data phase relationship among channels between multiple devices is
dependent on the Channel Sync Skew specification for each device. When utilizing
different models in a multi-device system, any differences in the ADC filter delay
(“Input Delay”) should be added.
Reference Note: For detailed information refer to the Encore software‟s Comprehensive Help.
You can access the Help from within Encore. After doing so, navigate to the synchronization
related topic as follows from the Help‟s Contents panel:
Configuring Hardware>>Hardware Setup>>Synchronizing Devices.
TO ACQ
TO ACQ
TO ACQ
TO ACQ

6224 User’s Manual General Information 1-5
Stacking Plate and Handle Options
6000 Series device chassis are equipped with feet (on the lower panel) and dimples (on the upper panel) to allow for
quick stacking of units.
A rigid securing of two or more units together is possible with the use of optional stacking plate kits (190658A-01).
Each kit contains two stacking plates and eight screws (8-32 x .500 in., Phillips Flat, 82 Degree). If needed,
additional kits can be used to stack and secure more devices.
An optional handle kit (HA-210-5-BK) is available to provide a convenient way of carrying a single 6000 Series
device or a secured stacked set of devices. Each handle kit includes one black molded plastic handle and two
mounting screws (1/4-20 x 7/8 in., Phillips Pan Head).
To attach two or more 6000 Series devices to each other using stacking plates:
1. Align the bottom two holes of a plate (hole tapers facing out) with the top two center holes of the lower
6000 Series device.
2. Secure the plate with two 8-32 x .500 in. Phillips screws (provided). Tighten the screws snug, but do not
over-tighten.
3. Repeat steps 1 and 2 for the second plate, on the other side of the 6000 Series device.
4. Attach the second 6000 Series device using the remaining four screws.
5. Repeat these steps with other stacking plate kits and devices as applicable.
To mount a handle:
Attach the handle to a 6000 Series device using the two outer holes on the device and the two 1/4-20 x 7/8 in.,
Phillips Pan Head screws (provided). Tighten the screws snug, but do not over-tighten.
Handle
(from kit HA-210-5-BK)
Stacking Plate (1 of 2)
(from kit 190658A-01)
6000 Series Devices

1-6 General Information 6224 User’s Manual
Quarter-Bridge Completion Accessories (CN-269 & CN-270)
The CN-269 and CN-270 are Quarter-Bridge Completion kits, with each kit
consisting of four components. A single component (each member of its
respective four-pack) can be used to add a Quarter-Bridge completion resistor
to a channel on the 6224.
The CN-269 components each house a 120 ohm resistor.
The CN-270 components each house a 350 ohm resistor.
You will need an RJ50 M/M cable to use any of the Quarter-Bridge
components with an 6224. Measurement Computing offers a pack of four
RJ50 M/M, 1 meter (3.28ft) cables (see upcoming RJ50 Cables section).
As indicated in the right-hand figure below, CN-269 and CN-270 components each have two holes that can be used to loop a
plastic tie-strap through, as a means of adding strain relief for the wire connections to the screw terminals.
If you want to mount a component, use a M4x20 screw (or similar hardware) that can fit into the 8.89 mm (0.350 in.) outer
clearance/4.57 mm (0.180 in.) inner clearance hole. See figure.
Specifications
(typical for the range -40 to 70 °C)
Weight ................................................ 32 g (1.1oz) per single component
Operating temperature .................... –40 to 70 °C
Resistor values:
CN-269 .......................................... 120 Ω
CN-270 .......................................... 350 Ω
Resistance drift:
CN-269 .......................................... 0.012 Ω/°C
CN-270........................................... 0.035 Ω/°C
Resistor tolerance (at 25 °C) ............... 0.1% max
Resistor power .....................................0.25 W max
Do not connect an RJ45 plug to an RJ50 jack. Using RJ45 plugs can cause
permanent damage to RJ50 pins 1 and 10, thus disabling shunt calibration.

6224 User’s Manual General Information 1-7
RJ50 12-Pin Screw Terminal Accessory (CN-268)
This accessory is used for Half-Bridge or Full-Bridge completion. Because bridge
completion is built into the 6224, you will only need connectivity accessories.
The CN-268 is a set of four female RJ50 to 12-pin screw terminal adapters. You
will need an RJ50 M/M cable to use a CN-268 component with an 6224.
Measurement Computing offers a pack of four RJ50 M/M, 1 meter (3.28ft) cables
(see following RJ50 Cables section).
As indicated in the right-hand figure below, CN-269 and CN-270 components each have two holes that can be used to
loop a plastic tie-strap through, as a means of adding strain relief for the wire connections to the screw terminals.
If you want to mount a CN-268 component, use an M4x20 screw (or similar hardware) that can fit into the 8.89 mm
(0.350 in.) outer clearance/4.57 mm (0.180 in.) inner clearance hole. See figure.
Specifications:
Weight ...................................................... 43 g (1.5oz)
Operating temperature ............................ –40 to 70 °C
Do not connect an RJ45 plug to an RJ50 jack. Using RJ45 plugs can cause
permanent damage to RJ50 pins 1 and 10, thus disabling shunt calibration.
RJ50 Cables (CA-272-01)
When connecting a cable from an 6224 RJ50 jack to an associated Measurement Computing accessory (CN-268, CN-269,
or CN-270), be sure to only use RJ50 M/M cables. Use of another cable type can damage RJ50 pins.
The CA-272-01 includes four RJ50 to RJ50 M/M, 1 meter (3.28ft) cables.
Pin 10
Pin 1
P1
P2
1 m (3.28ft)

6224 User’s Manual Block Diagram 2-1
Block Diagram 2

6224 User’s Manual Pinouts and Connectors 3-1
Pinouts and Connections 3
Strain Channels, RJ50 Pinout …… 3-1
Bridge Connections …… 3-2
Connecting TEDS Channels …… 3-2
Remote Sensing …… 3-2
Shunt Calibration …… 3-3
Internal Excitation Voltage Sources …… 3-3
External Excitation Voltage Sources …… 3-4
Mounting and Securing Connections …… 3-5
Where to Find Additional Information …… 3-5
Strain Channels, RJ50 Pinout
The twelve RJ50 (10p10c) jacks each have 10 pins with signal designations as indicated in the following table.
RJ50 (10p10c) Modular Plug and Jack Pinout
Pin #
Signal Name
Signal Description
RJ50
Front View
1
SC
Shunt Calibration
2
AI+
Positive Input Signal
3
AI-
Negative Input Signal
4
RS+
Positive Remote Sense Signal
5
RS-
Negative Remote Sense Signal
6
EX+
Positive Excitation Signal (Note 1)
7
EX-
Negative Excitation Signal (Note 1)
8
T+
TEDS DATA (Note 2)
9
T-
TEDS Return (Notes 1 & 2)
10
SC
Shunt Calibration
Note 1: The three channel blocks each share three signals [within their block], as follows:
For CH1, CH2, CH3, and CH4, the signal values of pins 6, 7, and 9 are shared.
For CH5, CH6, CH7, and CH8, the signal values of pins 6, 7, and 9 are shared.
For CH9, CH10, CH11, and CH12, the signal values of pins 6, 7, and 9 are shared.
Note 2: The 6224 only supports TEDS if the acquisition software being used supports TEDS.
Do not connect an RJ45 plug to an RJ50 jack. Using RJ45 plugs can
cause permanent damage to RJ50 pins 1 and 10, thus disabling shunt
calibration.

3-2 Pinouts and Connections 6224 Users Manual
Bridge Connections
The following figures indicate how to connect bridges to an the 6224. The manner in which these
signals correspond to the RJ50 connector is shown on the preceding page.
Quarter-Bridge
Half-Bridge
Full-Bridge
Notes:
(1) When connecting a bridge to the 6224, the following connections are optional: RS+, RS-, SC, T+, T-.
(2) For the half-bridge and quarter-bridge, there is no AI- signal to connect.
(3) To create a quarter-bridge, place an external resistor across the two SC lines of a half-bridge. Measurement
Computing offers two external Quarter-Bridge accessories, CN-269 (120 ohm) and CN-270 (350 ohm). See
chapter 1 for additional information regarding these accessories.
(4) Chapter 7 contains additional bridge information, including diagrams of the various bridge types that can be
selected in Encore and whether they apply to axial and/or bending strain.
Connecting TEDS Channels
Before connecting TEDS, be sure that your software supports TEDS. If it does, when connecting
TEDS ensure that neither TEDS data (T+) nor TEDS return (T–) is tied in common to any AI signals
on the 6224. See preceding schematics.
Remote Sensing
Wire resistance can create errors in bridge circuits. The
6224 can correct for these errors using two mechanisms: (1)
Remote Sensing and (2) Shunt Calibration.
Remote sensing continuously and automatically corrects for
errors in excitation leads, and generally is most appropriate
for full- and half-bridge sensors.
Long wire and smaller gauge wire have greater resistance,
which can result in gain error. The voltage drop caused by
wire resistance in the wires, which connect the excitation
voltage to the bridge, is a source of gain error. The 6224
includes remote sensing to compensate for this error.
Remote sense (RS) wires are connected to the point where
the excitation voltage wires connect to the bridge circuit, as
seen in the figure.

6224 User’s Manual Pinouts and Connectors 3-3
In the preceding figure, the actual bridge excitation voltage is smaller than the voltage at the EX+ and EX–leads.
If remote sensing of the actual bridge voltage is not used, the resulting gain error is as follows:
Error in Full-bridge sensors = 2RLead/RBridge
Error in Half-bridge sensors = RLead/RBridge
If the remote sense (RS) signals are connected directly to the bridge resistors, then the 6224 senses
the actual bridge voltage sense and eliminates the gain errors caused by the resistance of the EX+ and EX–leads.
Shunt Calibration
The second mechanism [aside from remote sensing] used to correct errors from wire resistance is Shunt
Calibration. This involves simulating the input of strain by changing the resistance of an arm in the bridge.
This is accomplished by shunting, or connecting, a large resistor of known value across one arm of the
bridge, creating a known strain-induced change in resistance. The output of the bridge can then be
measured and compared to the expected voltage value. The results are used to correct gain errors in the
entire measurement path, or to simply verify general operation to gain confidence in the setup.
Shunt calibration can be used to correct for errors from the resistance of both the excitation wiring and
wiring in the individual resistors of the bridge. Shunt calibration is most critical when measurements are
made on Quarter-Bridge sensors because there is no means to remotely sense around any IR drops in the
connection wiring.
The 6224 includes a precision 100kΩ resistor and a software-controlled switch for each channel. You can
leave the shunt calibration terminals connected to the sensor, and then apply or remove the shunt
calibration resistance in software.
While remote sensing corrects for resistances from the EX terminals on the 6224 to the sensor, shunt
calibration corrects for these errors and for errors caused by wire resistance within an arm of the bridge.
A stable signal, which is typically the unloaded state of the sensor, is used first with the shunt calibration
switch OFF, and then again with the switch ON. The difference in these two measurements provides an
indication of the gain errors from wiring resistances and corrections for offset errors.
Internal Excitation Voltage Sources
The 6224 houses three internal voltage sources; each serves 4 channels. The first source applies excitation voltage to
CH1 through CH4, the second to CH5 through CH8, and the third to CH9 through CH12.
The sensor industry does not recognize a single standard excitation voltage level. However, excitation voltage levels
residing in the range of 2.5V to 10 V are common. Encore’s selections for internal excitation are 2.5V, 3.3V, 5V,
and 10V, and each of the three internal voltage sources can provide up to 150 mW of excitation power. The 6224
automatically reduces internal excitation voltages, as needed, to stay below 150mW.
Since channels are associated by groups of four, the excitation setting applied to one channel in a group will also be
applied to the other channels in that group. As an example: if channel 1 is set to have and internal excitation of 3.3V,
then channels, 2, 3, and 4 will also have 3.3V excitation.
The 6224 measures the ratio of bridge output to bridge excitation, and as such does not require accurate excitation
voltage. For this reason the excitation voltage is not precisely regulated and may vary as much as
10% from the requested voltage, while still achieving accurate measurements.

3-4 Pinouts and Connections 6224 Users Manual
The power consumed by a single bridge is Vex
2/R
Where Vex is the excitation voltage and R is the total resistance of the bridge.
For a full bridge, R is equal to the resistance of each element. For a half or quarter bridge, R is equal to two times
the resistance of each element.
For each of the three voltage sources, the 150 mW limit allows you to power full and half bridges as follows:
Four 350 Ω half bridges at 5.0 V, or
Four 350 Ω full bridges at 3.3 V, or
Four 120 Ω half bridges at 2.5 V
If you need an excitation voltage greater than 150 mW, use the four-position external excitation voltage connectors
(see following section). Each of the three external connectors can be used to provide external excitation to four
channels of the 6224; thus all twelve channels can receive external excitation.
External Excitation Voltage Sources
The 6224 front panel includes three 4-pin connectors which provide a means of connecting external excitation
voltage sources.
Each external voltage source serves 4 channels, as follows; the first source applies excitation voltage to CH1
through CH4, the second to CH5 through CH8, and the third to CH9 through CH12. Since channels are associated
by groups of four, what you set for one channel (in a group) will also be applied to other channels of that group.
Example: if you set channel 1 for 10V external excitation, channels, 2, 3, and 4 will also have 10V external
excitation.
The sensor industry does not recognize a single standard excitation voltage level. However, excitation voltage levels
residing in the range of 2.5V to 10 V are common.
Unless you supply external excitation voltage, we recommend that you set the excitation voltage
to a value that keeps the total power below 150 mW.
The pinout and manufacturing information for the external excitation voltage source connector follows.
Contact Measurement Computing for more information.
Manufacturer Information
Molex Mating Connector
4-position housing (43025-0400)
Crimp terminal (43030-0007)
Also see the preceding section, Internal Excitation Voltage Sources.
-+
Silkscreen polarity orientation
markers visible on 6224 chassis
Top of Chassis

6224 User’s Manual Pinouts and Connectors 3-5
Mounting and Securing Connections
For a strain measurement system "mechanical noise" should also be a consideration. Movement in the
connection system could translate to errors in the measurement.
Care should be taken to ensure the 6224, RJ50 cables, and dongles are physically secured to prevent
relative movement.
Where to Find Additional Information
For detailed information, refer to the applicable software documentation, including software help files. Note
that the Encore software includes both a Context-sensitive Help and access to a Comprehensive Help
document.
In addition to software documentation, information regarding aliasing, anti-aliasing, sensors, accelerometers,
sound and vibration, and transducers may prove useful to your application. The internet is a great source for
this material.
In regard to TEDS (Transducer Electronic Data Sheet), you may find the IEEE 1451 standard to be
of interest.

6224 User’s Manual Counter Input 4-1
Counter Input 4
The 6224 has four 32-bit counter inputs that accept frequency inputs up to 20 MHz. The counter inputs are
individually configurable for counter or encoder measurements.
You activate each input, enable logging, and configure counter options with Encore.
Counter Settings
Counter Source
The source to use for the counter. Choices are:
Internal Clock
Timer 1
Timer 2
Digital Line 0 –Digital Line 7
One source can be used in multiple counters.
Counter Gate
The gate to use for the counter. Choices are:
Unused (do not gate the counter)
Internal Clock
Timer 1
Timer 2
Digital Line 0 –Digital Line 7
One gate can be used in multiple counters.
Count Settings
The functions or values for the counter source. Choices are:
Clear on Read –The counter counts up and is cleared after each read. By default,
the counter counts up and only clears the counter at the start of a new scan
command. The value of the counter before it is cleared is latched and returned.
Totalize –The counter counts up and is cleared at the start of a new scan.
Start Count value –The value used to start counting. The default is zero.
Stop Count value –The value used to stop counting. The default is 65535.
Rollover –The count rolls over upon reaching the start or stop value.
Counter Source
Direction
The direction in which to count. Choices are:
Increment –Count up (default).
Decrement –Count down.
Counter Source
Detection
The count to detect in relation to the signal edge. Choices are:
Rising Edge –Detects the count when the signal goes from low to high.
Falling Edge –Detects the count when the signal goes from high to low.