751-SG User manual - Windmill Software
Contents
1. Configure IML Hardware 23 Hardware Device Device 0 COMIML Edit this with comDebug before use Save Add IML Hardware xs Cancel Available Hardware Software Signal Generator a ComlML Serial Instrument Handler Add Windmill 750 Multifunction USB Unit Aad pt Windmill 751 Multifunction USB Unit Add IML device number 0 module number 0 Software 7 Directory Confiml 7 01 Copyright Windmill Software Ltd 2003 2011 Help Adding the 751 Unit The first thing you need to do is press the Add button to include your 751 unit 3 4 1 Adding New Hardware The Add IML Hardware dialogue lists the acquisition and control devices for which you have installed drivers Select the 751 Multifunction USB unit and press the Add button This will take you to the Hardware Settings dialogue Section 3 4 2 3 3 Microlink 751 User Manual 3 4 2 Changing Hardware Settings ConflML needs to know some information about your 751 unit Press the Help button or see below if in doubt about the answers Which Type of Card do you have Choose the 751 ID Code of the 751 Unit As you can connect several 751 units to your PC you need to tell ConflML which one you are currently configuring Do this by selecting the correct ID Code If you have only one 751 its ID Code is 0 There should be as many ID codes as there are 751 units connected and each code should be different If not change the2. 2 6 6 Pin Numbers Make the I O connections to the digital 37 way connector See the Pin Connections Table on page 2 10 2 7 Counter Connection Notes The 751 provides eight 16 bit totalise event counters which can each count up to 65535 These are located on Port 3 of the digital I O connector If you are using counters set Port 3 as an input only using the Windmill SetupIML software The 751 unit monitors the state of the 8 input lines once every milli second and maintains a count for each of them It does this whether or not you intend to use the lines as counters You can still read Port 3 as a normal digital input even if you are also using it to count 2 7 1 Input Voltages See Section 6 12 6 1 for safe voltage levels 2 7 2 Count Inputs A valid count is declared if the input is low for 2 milliseconds then high for two milliseconds This gives a theoretical maximum count speed of 250 Hz 2 7 3 Pin Numbers Make the counter connections to Port 3 of the Digital Connector The counter pin numbers are on page 2 10 2 8 Digital Input Output and Counter Pin Connections Table The pin numbers given on the next page are those for the digital 37 way D socket The analogue input pin numbers are on page 2 7 2 9 751 SG User Manual I li he 751 SG S 751 Pin Connections for 2 9 Measuring Strain Digital Inputs Outputs and Counters i F ai To measure strain plug the 594 into the 751 unit s analogue 19 o
3. 80 samples per second 0 02 100 MQ 2 18 Installing the 751 SG System 2 10 3 Digital Inputs and Outputs Maximum number of inputs Maximum number of outputs Power up state Maximum speed Voltage Inputs Compatibility Range Voltage Outputs Compatibility Drive 2 10 4 Counters Maximum number of counters Resolution Type of counters Maximum count speed Compatibility Input voltage range 32 32 all inputs 160 channels per second TTL and 5 V CMOS Oto5V TTL and 5 V CMOS 15 LSTTL loads 8 16 bits Event totalise 160 counts per second TTL and 5 V CMOS Oto5V 2 19 Installing and Configuring Windmill Software Installing and Configuring Windmill Software 3 1 Introduction There are two steps to installing and configuring the Windmill measurement and control software 1 Install the software onto the hard disk 2 Tell the software about your measurement hardware For installation you will need a personal computer with a USB port that is running Windows 98SE or later 3 2 What is Windmill Software Windmill is a ready to run suite of applications for data acquisition and control You can be up and running in very little time as no programming is required The standard suite includes data logging charting and output control applications You can also transfer data into third party applications like Microsoft Excel Access or Matlab Other Windmill modules are available see the Win
4. For strain measurements see Section 2 9 2 4 The 751 s Lights The 751 has two red lights labelled ENUM and BUSY Neither of these will come on until you have installed the Windmill software ENUM ENUM stands for Enumerated This is lit when the 751 has been powered on by the USB plug and play controller It is a good indication that the Windmill USB driver software has been correctly loaded BUSY This is lit for the duration of each USB communication It is not active until the has been enumerated 2 3 751 SG User Manual 2 5 Analogue Input Connection Notes The 751 provides 16 differential analogue inputs It also has an aux iliary channel which when used with the 594 box is reserved for bridge excitation monitoring It uses an integrating analogue to digital con verter where the integration time and resolution are under software control set in the Windmill ConflML program Section 3 4 At regular intervals Windmill uses a stable on board reference voltage for recalibration Use ConflML to set this recalibration interval 2 5 1 Differential Inputs All the inputs are differential for each input signal there are two signal wires The measurement is the difference in voltage between the two wires The two signals go into separate high impedance amplifiers which monitor the voltage between the input and ground The outputs of the two amplifiers are then subtracted to give the difference between the and inputs
5. codes on individual units as detailed in Section 2 2 Which Type of Transducer Connection Unit is Attached There are three options choose Strain Bridges Your 594 box monitors an external bridge excitation supply so that strain gauge outputs can be converted into readings in microstrain You can use channels not required for strain for general voltage measurement Select the Integration Time Resolution This allows you to select the trade off between speed precision and noise rejection Seven settings are available the slower the speed the better the precision and the more random noise is averaged out The exact speeds and resolutions vary with the computer transducer type and so on but the following table gives some typical figures 3 4 Instali 1 Configuring Windmill Sof Setting Typical Speed Voltage Resolution 12 bit 80 reads sec 5 mV in 10 V 13 bit 64 reads sec 3 mV in 10 V 14 bit 48 reads sec 1 5 mV in 10 V 15 bit 32 reads sec 0 8 mV in 10 V 16 bit 16 reads sec 0 4 mV in 10 V 18 bit 6 reads sec 0 1 mV in 10 V Settings from 15 bit to 18 bit will be effective at removing 50 Hz mains noise as these integrate over one or more complete mains cycles For strain measurement choose a high resolution The resolution figures show the ability to detect small changes The absolute accuracy will depend on several factors including your transducers Interval Between Automatic Recalibrations in Minutes This se
6. 751 SG User Manual Windmill Software Ltd Manual Code 751 SG 1 0 Issue Date January 2012 Information in this document is subject to change without notice For updates see http www windmill co uk help html Windmill Software Limited 2012 PO Box 58 North District Office Manchester M8 8QR UK Telephone 44 0 161 833 2782 Facsimile 44 0 161 833 2190 E mail sales windmillsoft com http www windmillsoft com Table of Contents Table of Contents Introduction Installing the 751 SG System 2 1 Introduction 2 2 Using Several 751 Units 2 3 Plugging the 751 into the Computer 2 4 The Microlink s Lights 2 5 Analogue Input Connection Notes 2 6 Digital Input and Output Connection Notes 2 7 Counter Connection Notes 2 8 Digital Input Output and Counter Pin Connections Table 2 9 Measuring Strain 2 10 Specifications Installing and Configuring Windmill Software 3 1 Introduction 3 2 What is Windmill Software 3 3 Installing Windmill Software 3 4 Configuring Your System Using Windmill Software with the 751 SG 4 1 Introduction 4 2 Options in SetupIML 4 3 The Rest of the Windmill Software Suite 1 1 2 1 2 1 2 1 2 2 2 3 2 3 2 8 2 9 2 9 2 11 2 18 3 1 3 1 341 S A 3 3 4 1 4 1 4 2 4 8 Introduction Introduction Thank you for purchasing the 75I SG Strain Measurement and Control Package This Manual tells you About the 751 SG system and how to connect your signal
7. For small signals differential inputs are much better than single ended inputs because the subtraction of the voltages on each of the input wires means that any voltage common to both wires is removed so reducing noise It is important to remember that the voltages at both inputs must be within the amplifier operating range A classic error is to connect a bat tery between positive and negative inputs with no other connection Although the difference between the inputs is well defined the actual voltage at each input could be anything Connecting one end of the bat tery to the O V input either direct or via a resistor would solve the problem The 0 V of the 751 is connected to computer earth which is usually connected to the mains earth When making your connections you should follow this policy a If your signal source is floating i e has no reference to mains earth then you must provide a reference by connecting one end of it to the O V input either direct or via a resistor The resistor could have any value up to several MQ However large values could 2 4 Installing the 751 SG System cause 50 Hz problems if your signal source has much leakage to earth b If your signal source is itself earthed then you should connect only positive and negative inputs You should make no connection to 751 earth 0 V pin 19 Floating Signal Channel input Source 751 Earthed Signal Ch
8. annel input Source 751 For floating signals you need to connect one end of the signal to the 0 V input on pin 19 2 5 2 Input Voltage Range The 751 operates correctly with input voltages in the range 11 V The inputs will reject voltages which are common to both positive and negative inputs These common mode voltages could be as big as 13 V 2 5 3 Maximum Input Voltage The input multiplexers are protected against dc voltages of 33 V above the power supply This means 48 V if the computer is switched on 33 V if it is switched off If the over voltage is transient then protection extends as far as 300 V When a voltage above the power 2 5 751 SG User Manual supply is applied to the unit its protection mechanism comes into ac tion and this draws some current from the signal source This effect can be a problem when the computer is switched off as it now draws current from any signal This current is limited by 4K7 resistors Extra series resistors can be added to reduce this fault current 2 5 4 Unconnected Inputs You can leave unused inputs unconnected but if you attempt to read from these unconnected inputs do not expect to get 0 V They could be any value If another connected channel has recently been read the unconnected input will return a similar value This is not crosstalk It occurs because the input capacitance of the amplifier is charged to the voltage of the previous channel a
9. citation These use 28 mA per bridge making a total of 0 45 A Connection of Power Supplies Power supplies are often floating devices i e they are not refer enced to mains earth If this is the case a connection must be made from 751 0 V to the power supply negative This can easily be done on the 594 If this is not done the bridge output voltages may be beyond the range of the 751 input amplifiers and false readings will result If several 594 units are used on a common power supply each should be given its own connection to the power supply This minimises the current flowing in any particular power supply wire and so reduces voltage drop in the wires 2 17 751 SG User Manual 2 10 Specifications 2 10 1 751 Unit Dimensions mm Maximum number of 751s Maximum length of cable 180 x 120 x 40 8 5 m per cable Maximum distance from PC can be increased by use of USB hubs 2 10 2 Analogue Inputs Number of inputs Maximum safe input voltage Computer on Computer off Transient Ranges set from software Common mode range Relative accuracy of ranges gain 1000 gain 1 10 100 16 48 V 33 V 300 V 10 V 1 V 100 mV 10 mV 13 V 0 1 0 05 A D performance set from software Resolution bits 12 13 14 15 16 18 Maximum speed of sampling up to a maximum of Maximum linearity error Input impedance Integration Time msec 2 5 5 10 20 40 160 10 samples per second per channel
10. decimal 11 3 3 1010 10 A 10001 17 11 11111111 255 FF Channels 0108 0118 0128 and 0138 are the direction control sig nals for ports 0 to 3 When set to 0 the whole port is used for input when 1 the port is used for output These channels can be viewed and also altered but they are normally disabled and must be explicitly en abled from SetupIML before use As noted above direction control can usually be sensed automatically by the software Channel 0109 0119 and 0129 are not used and cannot be enabled Using Windmill Software with the 751 SG 4 6 4 2 5 Event Counters The 751 unit provides eight 16 bit event counters The default names are 0200 0201 to 0207 Each counter starts at zero and counts pulses on the corresponding input lines to a maximum of 65535 They can be reset to zero at any time by sending 0 to the channel using the AnalogOut Graphics or Test Seq programs No other values can be sent to the counters Use SetupIML to change the names enable or disable each chan nel and choose one of two operating modes accumulating count or resetting count Accumulating Count Simply keeps counting until explicitly reset Resetting Count Starts again from zero after each reading This shows the num ber of pulses since the last reading but it can only be used where a single program is reading the counter If several differ ent programs were accessing the counter simultaneously they would all be rese
11. dmill Software Internet catalogue for details http www windmillsoft com 3 3 Installing Windmill Software 1 Connect the 751 data acquisition unit to your computer as detailed in Chapter 2 2 Install the Windmill software Insert the CD The Installation software should run automatically If not select Run from the Start menu and type d setup where d is your CD drive 3 1 Microlink 751 User Manual 3 When installation is complete the Windmill Configuration program ConflML automatically starts This asks for details of your hardware See Section 3 4 for details 3 3 1 Upgrading From Earlier Versions of Windmill You can run Windmill alongside earlier versions of the software Once you are happy that you no longer need a previous copy of Windmill simply run its Uninstall program to delete it 3 3 2 Running Several Copies of Windmill Unless you have bought a multiple licence you are only permitted to run one copy of the software at any one time Please contact your supplier or sales windmill co uk if you require a multiple licence 3 2 Installing and Configuring Windmill Software 3 4 Configuring Your System The Windmill Configuration program ConflML records the details of your data acquisition hardware It will run at the end of the installation process and you should run it again from Windows whenever your acquisition hardware changes for example when you install additional units
12. eral purpose input and output lines are ar ranged in 4 groups or ports Each port can be either input or output set using the Windmill SetupIML program All ports power up as inputs The ports are referred to as Port 0 to Port 3 Port 3 also functions as 8 event counters detailed in the next section 2 6 1 Input Voltages All inputs are high impedance CMOS type They are TTL and 5 V CMOS compatible Input Voltages should be within the range 0 to 5 V Higher Voltages can be dealt with by the addition of resistor networks This can be conveniently done on a 590 unit Input protection can be provided in a similar manner 2 6 2 Contact Closures You can interface to contact closures using a resistor to tie the input to either 5 or O V The contact then switches the line to either 0 or 5 V The resistor can be fitted to a 590 unit 2 6 3 Noisy Inputs Input Filters can be fitted to a 590 unit if required 2 6 4 Output Drive The outputs are TTL and 5 V CMOS compatible They can drive 15 LSTTL loads You can increase the output drive by using additional transistors which can be fitted to the 590 unit Currents of 1 amp can easily be switched 2 6 5 Power Up State The 751 unit will power up as all inputs If you intend to use the card to control outputs then you may want to define logic states at power up This can be done by resistors which tie the lines to either O or 5 V mounted on a 590 unit 2 8 Installing the 751 SG System
13. figure each channel as follows enable or disable set to one of six bridge configurations see below or set to read raw voltage re name set to a fixed range or allowing the software to pick the range automatically set to a gauge factor if transverse strain is being measured specify Poisson s ratio for the material under test set alarm levels See also the Special commands described on page 4 4 The supported bridge configurations are 4 2 Using Windmill Software with the 751 SG Quarter bridge One active gauge and three fixed resistors Half bridge One gauge measuring tensile strain E one measuring com pressive strain E and two fixed resistors Half bridge One gauge measuring normal strain E one measuring trans verse strain vE and two fixed resistors Poisson s ratio must be specified Full bridge Two gauges measuring tensile strain E and two measuring compressive strain E Full bridge Two gauges measuring normal strain E and two measuring transverse strain vE Poisson s ratio must be specified Full bridge One gauge measuring normal tensile strain E one measur ing normal compressive strain E one transverse tensile strain vE and one compressive transverse strain vE Pois son s ratio must be specified In all these cases the reading is reported directly in microstrain Channel 16 is used to read the bridge excitation voltage which m
14. ftware with the 751 SG 4 1 Introduction This chapter explains which settings in the Windmill SetupIML program apply to the 751 SG and about the rest of the Windmill soft ware suite You can use the 751 SG system to monitor voltages strain and blanced bridges like pressure transducers With additional 59x units you can also monitor currents and thermocouples Before starting Windmill make sure your 751 is plugged into the computer s USB port and if you are using a 593 strain measurement box that it is plugged into the 751 s analogue connector 4 1 Microlink 751 User Manual 4 2 Options in SetupIML SetupIML is the Windmill program that lets you save libraries of setup files each holding details about how you want to use individual channels A Windmill 751 is shown as three devices in SetupIML Analogue Inputs Digital Inputs and Event Counters Choose one from SetupIML s Device menu Now double click a channel to configure it Full details of using SetupIML are in its Help file 4 2 1 General Purpose Analogue Input Connector The input channels are numbered 0 to 15 Using SetupIML you can configure each channel as follows enable or disable re name set to a specific input range or allowing the software to pick the range automatically give a new units name scale factor and offset set alarm levels 4 2 2 Strain Gauge Bridge Connector The signal inputs are numbered 0 to 15 Using SetupIML you can con
15. it provides four digital ports each with 8 lines You can use each port for input or output You can explicitly control the choice or it can be deduced automatically by the software All ports start as in puts but if any data is sent to a port by a Windmill program it immediately switches to output mode Output lines can also be con trolled by the alarm detection features of the input channels This will cause the whole port to switch to output mode You can also use port 3 for event counting in which case you must set it as an input The channels are numbered as follows 0100 Line 0 of port 0 0101 Line 1 of port 0 0102 Line 2 of port 0 0107 Line 7 of port 0 0108 Direction control signal for port 0 0109 not used 0110 Line 0 of port 1 0111 Line 1 of port 1 0117 Line 7 of port 1 0118 Direction control signal for port 1 0119 not used 0120 Line 0 of port 2 etc In SetupIML you can replace the numbers with meaningful names By default each channel is linked to a single line and the two digital states are called ON and OFF You can change these names to more suitable ones for example FAST and SLOW or OPEN and SHUT SetupIML lets you group the lines within each port into multi bit channels which are displayed or controlled as single values transferred 4 5 Microlink 751 User Manual via the first channel in the group Multi bit values can be chosen as bi nary decimal or hexadecimal e g Binary Decimal Hexa
16. lects how frequently the software pauses to perform a recalibration of the 751 using its stable on board reference volt ages This will cancel any errors introduced by temperature or power supply changes since the last recalibration but can take up to a second to complete During this time no readings may be taken You can vary the interval from 1 to 1440 minutes 24 hours but every 20 minutes is generally sufficient 3 4 3 751 Devices After making your choices and pressing OK the ConflML Summary window appears showing your 751 as three hardware devices 751 analogue inputs 751 digital ports and 751 event counters 3 4 4 Setting the Default Folders the Working Directory When you use Windmill you will create two types of files those which hold data and those which hold the Windmill programs settings You can specify a default folder in which to store these files known as the Working Directory Initially the working directory is set to wherever you installed Windmill To change this press the Directory button 3 5 Microlink 751 User Manual Choose a new directory folder and press Save Windmill will cre ate two sub directories under this choice called setup and data All the Windmill settings will be stored in setup and all the data you collect stored in data 3 4 5 Saving the Settings Save your settings and they will be used every time you run Windmill You do not need to run ConflML again unless
17. nd has little incentive to change when connected to an open circuit 2 5 5 Auxiliary Input This input has all the facilities of the other sixteen In Windmill software it is used for measuring excitation voltage in bridge circuits When using a 594 bridge input unit the auxiliary input is automatically connected as required by the software 2 5 6 Analogue Input Pin Numbers Analogue inputs not being used for strain measurement are connected to the analogue 37 way D connector as detailed in the table on page 2 7 Installing the 751 SG System 15 V Auxiliary Input 15 Input 14 Input 13 Input 12 Input 11 Input 10 Input 9 Input 8 Input 7 Input 6 Input 5 Input 4 Input 3 Input 2 Input 1 Input 0 Please read the Connection Notes on the previous pages before making your connections 751 16 Analogue Inputs 37 36 35 34 33 30 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 OV 15V Auxiliary Input 15 Input 14 Input 13 Input 12 Input 11 Input 10 Input 9 Input 8 Input 7 Input 6 Input 5 Input 4 Input 3 Input 2 Input 1 Input 0 2 6 2 7 751 SG User Manual 2 6 Digital Input and Output Connection Notes The 751 provides digital input to the computer and output control by the computer Its 32 gen
18. ort 1 Bit 5 and monitor changes relative to that level Port 1 Bit 6 24 Sewers T 5 Port 1 Bit 7 With the 594 unit you can configure each input channel for any of 4 Port 0 Bit 1 the following inputs This can also be done at the factory for you Port 0 Bit 2 22 3 Port 0 Bit 3 i Port 0 Bit 4 21 voltage input z 2 Port 0 Bit 5 quarter bridge single strain gauge Port 0 Bit 6 20 half bridge tensile compressive strain gauge 1 Port 0 Bit 7 half bridge normal transverse strain gauge full bridge 2 tensile 2 compressive gauges Please read the Connection Notes on the previous pages before full bridge 2 normal 2 transverse gauges making your connections full bridge tensile normal compressive normal tensile transverse compressive transverse gauges 2 10 2 11 751 SG User Manual Installing the 751 SG System The figure on the next page shows the general arrangement of the 594 For each input channel 0 15 there are 5 screw terminals These are arranged in 5 rows labelled OV EX EX IN IN with channel number printed by each terminal Common to all channels are the POWER INPUT terminals and two precision resistors connected across the power supply to form a half bridge The power input termi EX nals are directly connected to the auxiliary channel of the 751 oe Er INpEt tin aux Windmill software reads the auxiliary channel to measure the exci tation voltage for use in the bridge equa
19. ows a quarter bridge connection The HX link connects the half bridge to the IN The RX bridge completion resistor must be fitted This resistor should be a high precision low temperature coefficient device Its value should be the same as the nominal resis tance of your strain gauge 120 and 350 Q being the commonest values In other applications it should be chosen to balance the bridge near the centre of your measurement range For instance if you are making precise RTD measurements around ambient temperature then 100 Q would be suitable If however you were monitoring higher tem peratures a suitably larger value would be chosen It is normal practice when making a quarter bridge connection to take all 3 wires to the transducer This balances out the effects of lead resistance POWER INPUT Strain Gauge in channel x gt POWER INPUT 594 Quarter Bridge Connection 2 16 Installing the 751 SG System Power Supply The bridges must be powered by an external power supply The voltage used should be chosen by the user to suit his application The current requirement can then be calculated as follows Full Bridge current voltage Rg where Rg gauge resistance usually 120 or 350 Q Half or Quarter Bridge current voltage 2 Rg Typical Examples 16 120 Q quarter bridges with 10 V excitation These use 42 mA per bridge making a total of 0 67 amps 16 350 Q full bridges with 10 V ex
20. s Chapter 2 How to install the Windmill software Chapter 3 How to use Windmill software with the 751 SG Chapter 4 To use the 751 SG system you need a PC with a USB port It should be running Windows 7 64 or 32 bit XP 2000 or 98SE With the 751 SG you can Monitor voltages strain and balanced bridges like pressure transducers With additional 59x units you can also monitor current and thermocouples Zero or balance bridges nulling the offset of the initial voltage and thus taking more precise measurements Record readings in microstrain or the engingeering units of your choice Switch digital inputs individually or several at once Count up to 65535 Choose input range and resolution 1 1 Installing the 751 SG System Installing the 751 SG System 2 1 Introduction The 751 SG system comprises A 751 data acquisition unit A 594 strain gauge connection box Windmill software The 751 unit lets you connect 16 analogue inputs 32 digital in puts outputs and 8 counters to your PC It has two 37 way con nectors 1 for analogue connections and one for ws ae digital and counter connections When measuring strain connect the 594 strain gauge box to the 751 s analogue connector with the ribbon cable You can then wire your strain signals to the 594 s screw terminals This chapter tells you how to connect your signals to the 751 After making your connections see
21. the next chapter for details of installing the Windmill software Make sure that you connect your hardware to the computer before starting Windmill 2 1 751 SG User Manual 2 2 Using Several 751 Units As you can connect up to eight 75x units to one PC each one must have some way of identifying itself an ID code 1 If you have just one 751 its ID code is 0 and you can ignore this section 2 If you add a 751 to your system you can set its ID code using 3 pins on the digital connector The pins in question are numbers 28 9 and 10 You set an ID code by connecting these pins to 0 V as follows ID Code Pin 10 Pin 9 Pin 28 0 no no no 1 no no yes 2 no yes no 3 no yes yes 4 yes no no 5 yes no yes 6 yes yes no 7 yes yes yes See the Pin Connections Table on page 2 7 for the location of the pins and 0 V Make a note of the ID Codes you ll need them when using Windmill ConflML to install the driver software For quick identification you may find it helpful to label your 751s with their codes Set the ID code before connecting the Microlinks to the PC 2 2 Installing the 751 SG System 2 3 Plugging the 751 into the Computer Plugging the into your PC could not be easier just use the USB cable provided You don t have to switch off your computer first or even restart gt gt Windows The 751 is powered from the USB port if you are not measuring strain you don t need an extra power supply box
22. tions Each channel has channel HB1 associated with it 2 link mounting positions and one resistor position IN Renee nee x 1K Ohm These are RX Position for mounting a quarter bridge completion resistor QX Link to short out the quarter bridge completion resistor HX Link to connect the half bridge to the IN of channel X IN in channel x C Hx 1K Ohm o HB2 in aux channel lt POWER INPUT Qx OV To OV Microlink Common i PER CHANNEL COMMON TO ALL CHANNELS General Arrangement of the 594 bridge inputs unit 2 12 2 13 751 SG User Manual Full Bridge Connection The figure below shows a full bridge connection The QX quarter bridge link must be fitted to connect the POWER INPUT to the EX Four wires are needed to connect your bridge and the earth is available for a cable screen POWER INPUT Strain All in channel x 594 Full Bridge Connection 2 14 Installing the 751 SG System Half Bridge Connection This figure shows a half bridge connection The HX and QX links must both be fitted The HX link connects the half bridge to the IN of the channel whilst the QX link connects the POWER INPUT to the EX Three wires are needed to connect your bridge and the earth is available for a cable screen POWER INPUT Strain in channel x screen 594 Half Bridge Connection 2 15 751 SG User Manual Quarter Bridge Connection The figure below sh
23. tting it at different times so the results would be unpredictable SetupIML also lets you apply a scale factor and offset to the count For example if the pulses came from a flow meter which produced one pulse for each 50 millilitres then a scale factor of 0 05 would give a reading in litres 4 7 751 SG User Manual 4 3 The Rest of the Windmill Software Suite The Windmill suite of software that comes with the 751 comprises ConflML SetupIML the display and control panels AnalogOut DigitalOut amp DDE Panel Logger and Chart The display and control panels let you send data to or display data from any number of analogue and digital channels Logger logs data to disk from up to 100 channels whilst Chart displays moving charts of data from up to 8 channels For more channels or different logging and charting speeds simply run more instances of Logger and Chart Full details of all these programs are given in their on line Help files and the Windmill User Manual Should you need more sophisticated analysis or presentation you can share data with other Windows applications using dynamic data exchange DDE For example you can process data as it s collected using Microsoft Excel See the DDE Panel Help file for more details There are many other optional programs in the Windmill range Graphics lets you design and create your own Windmill displays process mimics wiring diagrams bar charts annunicator pan els
24. ust be the same for all channels and is used in the calculations 4 3 Microlink 751 User Manual 4 2 3 Special Hardware Commands The channel dialogue boxes will have the Special button enabled This allows access to the following commands Recalibrate Forces an immediate recalibration of the whole board This is in addition to the periodic calibration cycles which happen automatically Cal_Interval Displays the time between automatic calibration cycles as selected in ConflML described in Section 3 4 Resolution Displays the resolution and integration time for this card as selected in ConflML described in Section 3 4 Show_Cal_Data Used only during manufacturer s test procedures When a strain gauge bridge is in use three additional commands are available Set_Zero_ Now This reads the bridge output ratio and uses it as the zero strain reference level All subsequent readings will be changes in strain relative to that point until another special command is issued or the software is closed down Describe Offset This shows the bridge output level which is currently being used as the zero strain reference level as a fraction of excitation voltage Disable_Offset Resets the zero strain reference to zero volts so absolute read ings are obtained This is the default state each time the soft ware starts running 4 4 Using Windmill Software with the 751 SG 4 2 4 Digital Ports The 751 un
25. v connector using its ribbon cable Port 3 Bit 0 37 18 Port 3 Bit 1 The 594 is a boxed 16 bridge inputs card which enables the 751 ROWS BIKE 29 17 Port 3 Bit 3 unit to monitor strain gauge bridges and balanced bridges such as Port 3 Bit 4 35 7 pressure transducers Extra facilities are available when components 16 Port 3 Bit 5 are fitted such as protection from high voltages Port 3 Bit 6 34 15 Port 3 Bit 7 For strain gauges you need an external excitation voltage that can Port 2 Bit 0 33 a ae i 14 Port 2 Bit 1 supply sufficient current to keep all the bridge circuits energised Four Port 2 Bit 2 32 sets of 16 screw terminals give and excitation and and signals 13 Port 2 Bit 3 for each of 16 bridges Two 1 kQ termination resistors are mounted in Porta Bita a 42 Port 2 Bit 5 half bridge configuration whilst high quality 350 and 120 Q resistors can Port 2 Bit 6 30 be provided for the completion of quarter bridges 11 Port 2 Bit 7 Not used 29 The auxiliary channel of the 751 unit monitors the excitation volt ID Code 0 28 1 1D Gode 2 age The A D converter is suitable for direct measurement of voltage 9 ID Code 1 imbalance provided you choose a high resolution Port 1 Bit 0 27 8 Port 1 Bit 1 When monitoring a bridge input the Windmill software automati Port 1 Bit2 26 cally reads excitation voltage and performs the bridge calculation to Port 1 Bit 4 25 FON LBIES produce a reading in microstrain You can set a zero reference level 6 P
26. whatever you wish Test Seq interprets a file of commands and controls a test rig accordingly Replay replays a data file graphically For details of other optional programs see http Awww windmill co uk programs html To be informed when new Windmill products are launched be given data acquisition hints and tips and read articles on measurement and control subscribe to the free Monitor newsletter ISSN 1472 0221 at http www windmill co uk newsletter html 4 8 5 1
27. you add more units or want to change the settings After closing ConflML start the SetupIML program and choose how you wish to use the hardware Refer to the next chapter and SetupIML s Help file setupiml hlp for details 3 4 6 The Software Signal Generator In addition to data acquisition and control hardware ConflML lists the Software Signal Generator This is a special driver which simulates a device with seven channels each channel producing a different sig nal No special hardware is required the data values are produced by calculation The Software Signal Generator lets you experiment and practise with Windmill without being concerned about the hardware To install the signal generator you first need to add it to the list of devices In the ConflML Summary window press the Add button Section 3 4 1 Select Software Signal Generator and again press the Add button You re taken to the Hardware Settings dialogue Section 3 4 2 where you can choose options for five of the channels Press the Help button in this dialogue for more information on the signal generator 3 4 7 The IML Device Icon Whenever you run a Windmill program one or more IML Device icons will appear Different icons identify different hardware drivers software signal generators and so on The Windmill applications can t run without these so don t close them whilst using Windmill 3 6 Using Windmill Software with the 751 SG Using Windmill So
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