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Model 205 User Manual - Applied Processor and Measurement, Inc.

1. Model 205 PWM Controller User s Manual This page intentionally left blank 1 6 Document No 00046 08 Rev C 2 0 Specifications Output Power Output Current Output Voltage Frequency 2 1 Open Drain Power MOSFET Example Output Current 100 duty cycle Power must not exceed maximum Pd Must use dual power supply configu ration for voltages not within PWM Controller Input range 1 to 1000 Hz adjustable in 1Hz steps 1000 to 10000 Hz adjustable in 50 Hz steps 10000 to 25000 Hz adjustable in 100 Hz steps Pd max 50 watts at 25 C 4A at 12V maximum 5V minimum 50V maximum max error lt 0 02 Hz for 1 Hz lt frequency lt 500 Hz max error lt 0 1 Hz for 500 Hz lt frequency lt 1000 Hz max error lt 10 0 Hz for 1000 Hz lt frequency lt 10000 Hz max error lt 50 0 Hz for 10000 Hz lt frequency lt 25000 Hz Model 205 PWM Controller User s Manual Duty Cycle Frequency Source Input Power Operating Temp 2 2 0 to 100 adjustable in 0 1 steps Crystal Oscillator Circuit 9V to 24V DC regulated or un regulated external source Dual supply required for operating loads outside this range Limited by LCD max error lt 0 01 duty over 1 Hz lt frequency lt 100 Hz max error lt 0 02 duty over 100 Hz lt frequency lt 1000 Hz max error lt 0 05 duty over 1000 Hz lt frequency lt 5
2. rape AC DC Adapter 12V DC Device Under Control Figure 3 0 3 PWM Controller Dual Supply Connection Additional Example Model 205 PWM Controller User s Manual Multiple loads may be tested using the PWM Controller An example is shown in figure 3 0 4 Figure 3 0 4 illustrates the connection for controlling 3 loads with the PWM Controller Any number of loads could be controlled provided that the total current of these devices is less than the maximum ratings defined in the PWM Controller specifications in Section 2 Host Computer PC PWM Controller Power Supply RS 232 Input Output 9 to 24 V DC es Devices Under Control Figure 3 0 4 PWM Controller Testing Multiple Loads Document No 00046 08 Rev C The PWM Controller may also be used to simply supply a variable fre quency and duty cycle square wave signal for a supervisory data acquisi tion and or control system One example of this would be to connect the PWM output to a device that is driven or controlled by a low level PWM signal For transmitting applications applications where the PWM duty cycle com mands a module of some type the PWM Controller can be wired to supply an output signal as opposed to driving a high current consuming load Since the PWM Controller has an open drain MOSFET output a load of some type is required to generate an output signal A resistor at the output termin
3. Command Report PWM Output Parameters Syntax R lt CR gt Parameters none Description The R command reports the current PWM pulse parame ters the frequency duty cycle polarity and operational mode Note that when operating in the Analog Input control mode the frequency and duty cy cle reported will be the settings that are derived from the analog input control signals as appropriate for the mode If the digital input mode is set to enable disable a 4th line will report the status of the digital input Example R lt CR gt reports output parameters Frequency 100 PWM Controller response 3 lines Duty Cycle 30 0L Mode Run Frequency 5050 PWM Controller response 4 lines Duty Cycle 49 7L Mode Run Output Disabled Command Stop Output Syntax S lt CR gt Parameters none Description The S command will stop the PWM Controller output The controller output will be forced to a permanently high or low output state de pending upon the polarity setting The PWM Controller will remain stopped until the E command is issued or the Mn Ad or An modes are enabled from the pushbutton interface Example S lt CR gt will stop the output Command Set or Report the Analog Control Duty Cycle Resolution Syntax V x x lt CR gt Parameters x X where x x 1 0 0 5 0 2 or 0 1 Description Use the V command to remotely set the pulse output duty cycle resolution when in analog control mode Note
4. 4 4 Document No 00046 08 Rev C 4 3 PWM Controller Operation 4 3 1 Front Panel Interface The PWM Controller is equipped with a front panel interface which pos sesses three pushbuttons for control of the PWM Output and a 2 line by 16 character Liquid Crystal Display LCD for display of the output parameters This section describes how to operate the PWM Controller using the front panel interface The PWM Controller may also be controlled using the remote port RS 232 interface The remote port may be used in conjunction with a PC running Windows HyperTerminal or a custom program All the operational capabili ties of the front panel interface are available via the remote port as well See section 4 3 2 for details on operation using the remote port There are three pushbuttons on the front panel interface for use in operat ing the PWM Controller they are labeled UP DOWN and SELECT Their function is defined as follows UP will change value by incrementing DOWN will change value by decrementing SELECT selects field on the display that UP or DOWN will operate on moves cursor The PWM Controller front panel interface uses a 2 line by 16 character al phanumeric LCD for display of the PWM Output parameters When the PWM Controller is powered on a sign on message will be dis played on the LCD The sign on message reports the PWM Controller Model Number the software version and the serial number of the unit Dur ing si
5. or design Please refer to our website at www appliedprocessor com for product updates software revisions and hard ware revisions Customers are welcomed to use the forms on the website to contact Applied Processor and Measurement Inc at any time for information on their product version potential future versions or customizations of the product for your particular application Copyright 2001 to 2009 by Applied Processor and Measurement Inc All Rights Reserved Document No 00046 08 Rev C REVISION HISTORY 2 16 01 ME Initial Release 10 7 05 As required Changes as per addition of a third fre quency range 50 to 2500 Hz in 50 Hz steps PWMC 205 Software Revision 2 21 5 18 07 As required Changes as per revision of hardware and software to rev 3 X C 2 5 09 2 3 3 12 Updated digital input specifications 3 11 4 18 Changes due to updated model num bers and options Model 205 PWM Controller User s Manual SAFETY SUMMARY THE FOLLOWING GENERAL SAFETY PRECAUTIONS MUST BE OB SERVED DURING OPERATION AND INSTALLATION OF THIS PRODUCT FAILURE TO COMPLY WITH THESE PRECAUTIONS AND WARNINGS HERE AND ELSEWHERE IN THIS MANUAL VIOLATES THE SAFETY STANDARDS OF DESIGN MANUFACTURE AND INTENDED USE OF THIS PRODUCT APPLIED PROCESSOR AND MEASUREMENT INC AS SUMES NO LIABILITY FOR THE FAILURE TO COMPLY WITH THE SAFETY RECOMMENDATIONS PROVIDED IN THIS MANUAL INTENDED USE The Model 205 Pulse Width Modulation Control
6. output binding posts attach cathode to anode to To remove the diode from the output circuit remove the back cover A black shorting jumper at JP1 is present on the circuit board near the fuse To remove the internal diode from the output circuit simply remove the jumper Note that the circuit board need not be removed from the top of the enclosure the diode jumper is completely accessible from the back of the unit by simply removing the back cover 3 3 RS 232 Connections The PWM Controller possesses an RS 232 port for remote operation capa bility The RS 232 port is available on the PWM Controller from the DB 9 connector on the upper right corner of the unit The pinout of the DB 9 is provided in table 3 3 1 Pins not shown in the table are not connected inter nally within the PWM Controller DB 9 Pin Number Transmit Data TXD Receive Data RXD Table 3 3 1 DB 9 RS 232 Remote Port Pinout To connect a host computer control system or PC to the PWM Controller use a cable wired as defined in table 3 3 2 This table provides connections to standard RS 232 connectors for PC s Both 9 pin and 25 pin versions are shown Note that fora PC with a DB 9 a straight through cable may be used Consult your PC or equipment manual for proper RS 232 pinout 3 9 Model 205 PWM Controller User s Manual PWM PWM PC DB 9 Pin DB 25 Pin Controller Controller Signal Signal DB 9 Pin Table 3 3 2 RS 232 Cable Wiring The re
7. CR gt R lt CR gt S lt CR gt V x x lt CR gt save configuration data set duty cycle to xxx x 0 0 100 0 increment duty cycle by 0 1 decrement duty cycle by 0 1 enable PWM output set frequency to xxxxx Hz set report analog frequency control range xxxxx 250 500 1000 10000 or 25000 set analog input control vrs compatibility 1 2 or 3 command help report system info Model No Serial No Software rev x 0 lock out x 1 enable pushbutton interface report pushbutton and analog input lock status set digital input mode x 0 off x 1 enable disable set duty cycle polarity high x 1 low x 0 report current freq duty cycle polarity and mode stop output set report analog control duty resolution Table 4 3 2 1 PWM Controller Remote Port Command Summary Model 205 PWM Controller User s Manual Command Analog Input Control Mode Select Syntax A x lt CR gt Parameters x where x 0 1 2 or F Description The A command sets the mode of the PWM Controller op eration using the analog input ports accessible on the 8 pin analog port con nector Use the parameter 0 for turning off analog input control Use 1 for enabling analog input control of the duty cycle only and 2 for enabling ana log input control of both the frequency and the duty cycle Sending com mands to a PWM Controller that is already operating in that mode will have no effect Note that the
8. Controller which is 0 1 every time that the command is received The PWM Controller will feedback no response no echo over the remote port The value of the duty cycle on the LCD will be updated Note that the function of this command is equivalent to using the pushbutton inter face with the cursor at the duty cycle position and pressing the UP pushbutton in the tenth place Also note that no lt CR gt is required Example will increase output duty cycle by 0 1 Command Decrement the PWM Output Duty Cycle by 0 1 Syntax Parameters none Description Use the key to decrement the pulse output duty cycle The output duty cycle will be decremented by the minimum step resolution of the PWM Controller which is 0 1 every time that the command is re ceived The PWM Controller will feedback no response no echo over the remote port The value of the duty cycle on the LCD will be updated Note that the function of this command is equivalent to using the pushbutton inter face with the cursor at the duty cycle position and pressing the DOWN pushbutton in the tenths place Also note that no lt CR gt is required Example will decrease output duty cycle by 0 1 4 9 Model 205 PWM Controller User s Manual Command Enable Output Syntax E lt CR gt Parameters none Description The E command will enable the PWM Controller output This allows the controller to operate in the normal manual mode or the
9. ana log input mode if enabled Note if the digital input enable disable control is used the output will be controlled by the digital input Example E lt CR gt will enable the output Command Set the PWM Output Frequency Syntax F xxxxx lt CR gt Parameters XXXXX where xxxxx 1 to 25000 Hz Description Use the F command to remotely set the pulse output fre quency The value xxxxx must be in the range of 1 to 25000 otherwise an error message will be returned The value be automatically coerced to the nearest value that is supported by the controller see section 4 2 1 The fre quency value supplied may be 1 to 5 characters in length leading zeroes are ignored This allows software formatting of the digits to be used in computer control applications For example a value for xxxxx of 00004 is equivalent to 4 The engineering units designation of Hz should not be typed Example F 00105 lt CR gt will set the output frequency to 105 Hz F 1040 lt CR gt will set the output frequency to 1050 Hz F 12345 lt CR gt will set the output frequency to 12300 Hz Command Set or Report the Analog Frequency Control Range Syntax G Xxxxx lt CR gt Parameters XXXXX where Xxx 250 500 1000 10000 or 25000 for V3 x software setting 250 500 2500 for V2 x software setting 200 or 400 for V1 x software setting none to report current setting Description Use the G command to remotely set the pulse output fre
10. as a two letter code under the status field on the LCD The characteristics of the four modes are as follows Run Manual Mn The PWM Output is operational output frequency duty cycle and duty cycle polarity are displayed and the output is operating at these settings Both the front panel interface pushbuttons if enabled and the remote port are active and ready to accept commands Changes requested by either interface shall be translated to the output and to the LCD immediately Analog Control of Duty Cycle Ad The PWM Output is operational output frequency duty cycle and duty cycle polarity are displayed and the output is operating at these settings Only the PWM output duty cycle is controlled by an analog input See sec tion 4 4 for details on the analog input voltage translation to duty cycle In Ad mode the front panel pushbuttons and the remote port RS 232 control 4 3 Model 205 PWM Controller User s Manual of frequency and duty cycle are disabled Changes may be made to the duty cycle polarity and the mode of operation from either the pushbuttons or the remote port Analog Control of Frequency and Duty Cycle An The PWM Output is operational output frequency duty cycle and duty cycle polarity are displayed and the output is operating at these settings The PWM output frequency and duty cycle are controlled by the analog inputs See section 4 4 for details on the analog input voltage translatio
11. field and then continue operation at its current set tings There is no need to power cycle the unit See section 4 6 for details on the configuration process Example CFN lt CR gt save configuration Document No 00046 08 Rev C Command Set the PWM Output Duty Cycle Syntax D xxx x lt CR gt Parameters XXX X where xxx x 0 0 to 100 0 in 0 1 increments Description Use the D command to remotely set the pulse output duty cycle The value xxx x must be in the range of 0 0 to 100 0 and represents steps The minimum step resolution of the PWM Controller is 0 1 The duty cycle value supplied may be 1 2 3 or 4 characters in length leading zeroes are ignored and the decimal is assumed to be zero when not present This allows software formatting of the digits to be used in computer control applica tions For example a value for xxx of 004 is equivalent to 4 The percent sign is not required and should not be used Example D 34 lt CR gt will set the output duty cycle to 34 Example D 0 7 lt CR gt will set the output duty cycle to 0 7 Example D 82 5 lt CR gt will set the output duty cycle to 82 5 Example D 2 lt CR gt will set the output duty cycle to 0 2 Command Increment the PWM Output Duty Cycle by 0 1 Syntax Parameters none Description Use the key to increment the pulse output duty cycle The output duty cycle will be incremented by the minimum step resolution of the PWM
12. ideas regarding the use of the PWM Controller Applied Processor and Measurement Inc welcomes information on your ap plication Feel free to FAX or e mail us a description of your application Our goal is to design and supply the products you need for your current and future applications A 1 Using the PWM Controller as a Signal Conditioner Beyond using the PWM Controller as a durability tester for electromechanical devices the controller may be used as a signal generating element This example illustrates a potential control system architecture using the PWM Controller as a signal conditioner As discussed in the User s Manual installation section the PWM Controller may be used as a signal conditioner signal generator for use in data acquisi tion and control systems This appendix section describes how this is accom plished and potential uses for this arrangement The application of pulse width modulation as a method of transmitting control information in electromechanical systems is steadily increasing Beyond us ing the PWM Controller as test equipment for durability and life cycle testing of devices the controller may be used as an interface for an electromechani cal control element As discussed in the installation section of this manual the PWM Controller will provide a PWM square wave signal by simply applying a load across the out put terminals of the controller This arrangement is shown in figure A 1 1 A resistor pro
13. output must be enabled with the E command for the A1 or A2 commands to have effect Sending the AF command shall disable the use of analog input modes entirely via the front panel interface This will limit the LCD display mode selections to Manual or Off The function is used to prevent inadvertent changes of the operating mode when the analog mode is not used Note that this does not program the configuration memory to set the analog mode disable on power up this must be set using the configura tion options see section 4 6 Example A 1 lt CR gt allows analog input control of duty cycle only Command Save PWM Output Configuration Syntax CFN lt CR gt Parameters none Description The CFN command is used to save the power on start up settings of the PWM Controller After a configuration is completed the PWM Controller will start up and operate using the last parameter settings saved in configuration memory The parameters saved are frequency duty cycle polarity mode analog control operating frequency range analog control oper ating duty cycle resolution analog control version compatibility pushbutton interface enable disable digital interface mode and analog input mode en able disable After the CFN command is sent the PWM Controller will stop operation for a few seconds while saving the parameters output fixed to a non engaged state based on the current polarity setting display Cf on the LCD screen in the status
14. stopped immediately even before the cycle is allowed to complete its period Note that when the digital input mode is enabled the digital input display field will be active on the LCD refer to section 4 3 1 The character position to the left of the mode field will display a lower case e or d when the digital input is enabled or disabled This allows the user to see whether the digital input is overriding the PWM output mode selected For example if the mode is displayed as manual Mn and the digital input is disabled a d will be dis played on the LCD and the output will be off When the digital input mode is not enabled set to none the display field for the digital input will be blank 4 4 PWM Controller Operation Analog Input Control The PWM Controller operating in one of the two Analog Input Control modes provides for adjustment of the operating frequency and duty cycle via analog inputs Note that there are two analog input control modes one mode con trols both the frequency and duty cycle the other controls only the output duty cycle only In the mode where only the duty cycle is controlled via the analog input the frequency must be set in the Run Mn mode or via configuration prior to using the analog input mode The analog input controls are connected via an 8 pin connector on the front left side of the unit For connector pinout see section 3 4 4 14 Document No 00046 08 Rev C The analog
15. system if common mode voltages are expected to be a problem isolation modules should be added to the system to isolate the control system from the analog input on the PWM Controller Typically industrial applications in test facilities and manufacturing areas may exhibit this phenomena Confined areas for example a desktop PC with a data acquisition and control card should not require isolation since a single AC source may be easily obtained and applied to the overall system For best results isolate the control signals use the dual power supply configuration see section 3 and use properly sized wiring for the load to be pulse width modulated The table below shows the signal translation from the PLC to the duty cycle output Current Output Voltage to PWM Duty Cycle Output mA Controller V 07040 0 800 30 20 4 000 Table A 1 1 Example Current to Duty Cycle Conversion Data Model 205 PWM Controller User s Manual The power source used for the PWM Controller is the 24V DC power supply available on the PLC In this example application the motor PWM control signal amplitude must be 12V 10 The PLC 24V DC supply powers the PWM Controller and supplies load power The 24V amplitude of the PWM signal generated is regulated down by the resistor zener diode net work which ultimately reduces the signal to the proper 12V level for the motor speed control By using this configuration the need for adding an external
16. updated on a cycle by cycle basis allowing the current PWM pulse period to complete its cycle before changing A power MOSFET out put transistor provides an open drain current sink for the device under con trol This MOSFET output stage is fuse protected to prevent damage to the MOSFET and or the output load being driven The PWM Controller in cludes an internal diode for suppressing back currents from inductive loads This diode may be removed from the circuit by removing a jumper in order to easily accommodate user diode configurations other than a S2BA 13 The PWM Controller analog input control capability is provided by an on board A D converter IC This 12 bit converter produces a digital represen tation of the frequency and duty cycle control inputs The microcomputer scales the digital representation in order to produce the proper frequency and duty cycle ranges The embedded controller software and configuration parameters are stored in re programmable FLASH memory This allows for field upgrade and customization of the PWM Controller see Section 5 via the serial port 4 1 1 Polarity Note the open drain output configuration with respect to the control of the load shown in the block diagram in figure 4 1 1 When the digital output of the internal microcontroller is logic low the MOSFET is off and the device load receives no current When the microcontroller bit is high the MOSFET is turned on allowing current to pass throu
17. 0 cece eeeeeeeeeeeeeeeeneeeeeenaeeeeeneeeeeenaeeeenaas 5 4 Appendix A Application Examples rrrvvrnrnnnvrrnrrnvrnnnvsvvnnnnnnrrnnrrnnnnn A 1 A 1 Using the PWM Controller as a Signal Conditioner A 1 A 2 Using the PWM Controller with a Laptop PC and a PCMCIA Data Acquisition Card A 4 A 3 Commanding the PWM Controller with PC Software A 6 Model 205 PWM Controller User s Manual List of Figures 3 0 1 PWM Controller Single Supply Connection 00 eee 3 1 3 0 2 PWM Controller Dual Supply Connection 00 0 eee 3 2 3 0 3 PWM Controller Dual Supply Connection Additional EXAM Pl EE cba N N Devs 3 3 3 0 4 PWM Controller Testing Multiple Loads essere 3 4 3 0 5 PWM Controller Connecting as a Signal Generator 3 5 3 0 6 PWM Controller Connecting as a Signal Generator device contains internal pullup ccceeeeeeeeeeceeeeeeeeeeeeeaeeeeeeeeeeeees 3 6 3 4 1 Analog Input 8 Pin Connector Pinout Orientation 00 0 3 11 4 1 1 PWM Controller Block Diagram ernnnnnnnnnrrrrnnnnrnnrnnrnnrnnnnnnnnn 4 1 4 1 1 1 PWM Controller Polarity Example rsrvrnrnnnrrrnvvvvrnnvvrrvnrrnnnr 4 3 A 1 1 PWM Controller Signal Conditioning Example A 2 A 2 1 PWM Controller PC PCMCIA Interface Example A 5 List of Tables 3 1 1 PWM Controller Maximum Recommended Output Fuse R tingsu skissen ae E sa cdevyoetecs tostecdesaecesavasege EE 3 8 3 3 1 DB 9 RS 23
18. 000 Hz max error lt 0 5 duty over 10000 Hz lt frequency lt 25000 Hz 40 0000 MHz 50 ppm stability 75 mA typical 5 C to 50 C Parameter Analog Control Analog Inputs Digital Input Display 2 3 Document No 00046 08 Rev C PWM Parameter Control Input Accuracy 5 mV Absolute Maximum Input Voltage Model 205 standard 5V input Model 205 10V input option Maximum Input Voltage for Output Enable Minimum Input Voltage for Output Enable Maximum Current internal 1 65k ohm resistor TX RX GND 9600 baud no parity 8 data bits 1 stop bit DB9 M 7 5 in x 4 in x 1 1 in height 2 1 in height by LCD 2 Line x 16 Character Liquid Crystal Model 205 PWM Controller User s Manual This page intentionally left blank 2 4 Document No 00046 08 Rev C 3 0 Installation WARNING FOLLOW THE INSTALLATION INSTRUCTIONS CAREFULLY TO AVOID POSSIBLE DAMAGE TO THE PWM CONTROLLER TO YOUR LOAD DE VICE OR SYSTEM UNDER CONTROL REMEMBER TO PROPERLY SE LECT ALL WIRE SIZES FROM THE POWER SOURCE TO THE PWM CON TROLLER OUTPUT AND TO THE DEVICE UNDER CONTROL IN ORDER TO MINIMIZE HAZARDS AND TO PROVIDE A SUITABLE RETURN PATH FOR INDUCTIVE LOADS This section provides installation instructions and figures which illustrate typi cal connections for the PWM Controller and the device to be controlled Figure 3 0 1 shows connection of the PWM Controller to a single device using a single po
19. 2 DATA 0x02f8 define COM2 STATUS 0x02fd define XMT RDY 0x20 define RCV_RDY 0x01 char b int com stat send command b 0 do com stat inport COM2 STATUS if com stat amp XMT RDY b cptr outport COM2 DATA b while b n get response wait for the prompt do com stat inport COM2 STATUS if com_stat amp RCV_RDY b inport COM2 DATA while b return A 8
20. 2 Remote Port Pinout 3 9 3 3 2 RS 232 Cable Wiring 00 cece ceeeceee cents eeeneeeeeeeeeeesneeeeeeaaes 3 10 3 4 1 Analog Input Port Pinout eeens 3 11 4 3 2 1 PWM Controller Remote Port Command Summary 4 7 4 4 1 Frequency vs Analog Input V3 x Compatibility 4 16 4 4 2 Duty Cycle vs Analog Input V3 x Compatibility 4 16 4 4 3 Frequency vs Analog Input V2 x Compatibility 4 17 4 4 4 Frequency vs Analog Input V1 x Compatibility 0 4 17 4 4 5 Duty Cycle vs Analog Input V2 x and V1 x Compatibility 4 17 A 1 1 Example Current to Duty Cycle Conversion Data vi Document No 00046 08 Rev C 1 0 Introduction This manual describes the features operating parameters and operating procedures for the Model 205 Pulse Width Modulation Controller PWM Con troller or PWMC The Model 205 Pulse Width Modulation Controller generates a pulse width modulated variable frequency and duty cycle electrical switching signal The product is used in many industrial situations where valves solenoids actua tors or other magnetic mechanical elements are applied and or tested The PWM Controller contains microcomputer based circuitry and digital Field Programmable Gate Array technology which allows for precision generation of the output frequency and duty cycle The microcomputer also provides digital control of the output parameters via the switches on the front panel Using the switche
21. PLC Programmable Logic Controller 4 6 Document No 00046 08 Rev C When the PWM Controller is powered on a sign on message will be trans mitted out the serial interface During this time the PWM Output will begin operating at the default or configured settings see section 4 6 on Configu ration After the sign on message is complete a star prompt will be transmitted signifying that the controller is ready for commands Features of the PWM Controller are controlled via a command set that is ASCII character based All commands are terminated by a carriage return Return or Enter Key on your keyboard ASCII value of 13H A command summary is shown in the table below The carriage return is shown as lt CR gt Detailed descriptions of the instructions follow Note that in all cases spaces are ignored No other punctuation or symbols should be used Characters may be any combination of uppercase or lowercase char acters All numeric values shown are ASCII character representation of numbers that is the number 100 is actually three ASCII characters 1 0 and 0 All numbers are represented in base 10 analog input mode select x 0 off x 1 control freq and duty x 2 control duty only x F disable CFN lt CR gt D xxx x lt CR gt E lt CR gt F xxxxx lt CR gt G xxxxx lt CR gt GV x lt CR gt H lt CR gt lt CR gt K x lt CR gt L lt CR gt M x lt CR gt P x lt
22. USER S MANUAL MODEL 205 PULSE WIDTH MODULATION CONTROLLER DOCUMENT NO 00046 08 REV C d gt ag Applied Processor and Measurement Inc Document No 00046 08 Rev C THANK YOU Thank you for purchasing the Applied Processor and Measurement Inc Model 205 Pulse Width Modulation Controller Applied Processor and Measurement Inc is pleased to provide this high quality feature rich and value minded test equipment for use in your labora tory We appreciate your business and look forward to serving you for many years to come with both the Pulse Width Modulation Controller and other fu ture equipment equally as innovative Applied Processor and Measurement Inc is committed to customer satisfac tion and continuous improvement We welcome your comments on the prod uct and our services Please use the contact forms on our website for com ments on the product and on this manual Again thank you for purchasing and using our product Model 205 PWM Controller User s Manual NOTICE The information contained within this manual has been carefully checked and is believed to be accurate and up to date Applied Processor and Measurement Inc operates under the guidance of quality standards which include activities governing continuous improvement Applied Processor and Measurement Inc may in the future make changes to this product or this manual without notice to improve the product reliability performance function
23. able 3 4 1 Analog Input Port Pinout Figure 3 4 1 illustrates the 8 pin connector pinout as viewed when looking directly at the connector from the left side of the PWMC unit 87654321 Figure 3 4 1 Analog Input 8 Pin Connector Pinout Orientation Operation using the Analog Input for control of the PWM Output Frequency and Duty Cycle is described in the Operation section of this manual section Standard Model 205 PWM Controllers provide frequency and duty cycle adjust single ended analog inputs where the reference input is the controller ground shared on pin 4 Model 205 PWM Controllers with the DF option have differential inputs for the analog inputs The inputs are fully differential so as to protect against ground loops in control system PLC applications Neither input is con nected together internally and the input is not connected to the control ler ground 3 11 Model 205 PWM Controller User s Manual Operation using the Digital Input for control of the PWM Output enable or disable is described in the Operation section of this manual section 4 3 3 Note that the Digital Input is optically isolated from any of the controller sig nals including power and ground The input contains a series resistor to limit input current to the opto isolator LED 5V is available on the analog port for peripheral electronics A potentiome ter may be powered by this 5V output to control the frequenc
24. als is sufficient The figures below show how to connect the PWM Controller as a signal generator There are two configurations shown de pending on the configuration of signal destination internal pull up or not To use the PWM Controller as a signal generator connect the unit as shown in figure 3 0 5 or 3 0 6 for equipment with an internal pull up PWM Controller Device OUT OUT V GND Power Supply Figure 3 0 5 PWM Controller Connecting as a Signal Generator Model 205 PWM Controller User s Manual PWM Controller Device OUT OUT INPUT with internal pullup resistor V GND Power Supply Figure 3 0 6 PWM Controller Connecting as a Signal Generator device contains internal pull up Note that with respect to the PWM Controller a 100 duty cycle means that the MOSFET output is on and the voltage at the device input will be OV At 0 the output will be floating or pulled up to V by the internal or exter nal resistor This inversion may be compensated for in the Model 205 by using the Polarity setting function Finally V can be any voltage within the range of the PWM Controller input voltage requirements 9 to 24V Document No 00046 08 Rev C Note that the signal generation configuration may also be used to supply a signal which drives the gate of a higher power rated v
25. auk a aiaa ap asas edia riit parune 1 3 1 3 Applications iniiae iaai eiai aa 1 5 2 0 Specifications ig csetecewcscetha mig nbeetidipedaee sueesdulebetacnetices 2 1 3 0 JInstallation secriec cettet iniesta a tease ce keel 3 1 BEV FUSING PAER content cde sorva E 3 8 3 2 InternalDiod s 22 seczcpcs sees ea aana eiia 3 9 3 3 RS 232 Connections rrnrarvvvvnnnnnvrvnrrnvrnnrrrvrnnrrnrrrenrrnnnn 3 9 3 4 Analog Input Connections ursssvvrerenvrrnvvrvvrnrrvvrvnnrren 3 10 4 0 Operatl n sendere eeo sgehenta sua stein ssacdebapunapeasaees 4 1 4 1 Theory of Operation irissen ita 4 1 4 1 1 Pol rity etnea a Prasad 4 2 4 2 PWM Controller Operation Operational Modes 4 3 4 2 1 PWM Controller Operation Frequency Setting 4 4 4 3 PWM Controller Operation seenen 4 5 4 3 1 Front Panel Interface rursnvnnnnnvvvnnnnnnvrnnrrnnrnnnvrvvnnrnn 4 5 4 3 2 Remote RS 232 Interface rrrrrnnrnrrnnnnnnrrnnrnrrnnnnr 4 6 4 3 3 PWM Controller Operation Digital Input Control 4 14 4 4 PWM Controller Operation Analog Input Control 4 14 4 5 PWM Controller Operation Precedence 06 4 18 4 6 PWM Controller Configuration 4 19 5 0 Warranty and Service eee ceeeseeeceeeeeeeenneeeeeeaeeeeeneeeeeenaeeeeeenas 5 1 5 1 A Ta Ke IN EEE AE E ETE T 5 1 5 2 Service ienai i i an i ea a ida 5 1 5 3 DiagNoStCS inoseni i ai a anA anai 5 2 5 4 Software Upgrades Updates l enn 5 3 5 5 Customization
26. control signal varies the frequency or duty cycle at a rate of mV per Hz and mV per percent duty cycle dependent on the range and resolution selected The adjustments are also dependent upon the software compatibil ity setting Version 3 x 2 x or 1 x The software version compatibility setting allows for backwards compatibility for existing analog control installations us ing the Model 205 unit Use the G and GV commands to set the range and compatibility settings see section 4 3 2 or the power on configuration menu see section 4 6 The analog control mV input to output relationships are given in the equations and tables that follow Output Analog Control Equations version 3 x software compatibility Output Freq Voltage Input 0 020 1Hz 250 Hz range Output Freq Voltage Input 0 020 2 Hz 500 Hz range Output Freq Voltage Input 0 020 5 Hz 1000 Hz range Output Freq Voltage Input 0 020 50 Hz 10000 Hz range Output Freq Voltage Input 0 020 100 Hz 25000 Hz range Output Duty Cycle Voltage Input 0 050 1 0 1 0 resolution Output Duty Cycle Voltage Input 0 025 0 5 0 5 resolution Output Duty Cycle Voltage Input 0 010 0 2 0 2 resolution Output Duty Cycle Voltage Input 0 005 0 1 0 1 resolution Output Analog Control Equations version 2 x software compatibility Output Freq Voltage Input 0 016 1 Hz 250 Hz range Output Freq Voltage Input 0 016 2 Hz 500 Hz ra
27. de lt time h gt char cptr void main void int duty index char a time t t unsigned long tmp printf nPWMC Demo Durability Test Controller n printf Hit any key to stop n n init PWMC cptr F 100 n out freq fixed at 100 Hz sendcmd A 6 cptr P sendcmd cptr E sendcmd duty index do switch 0 Document No 00046 08 Rev C low polarity enable output duty_index case 0 ptr prin brea case 1 cptr prin brea case 2 Spree prin brea case 3 optr prin brea case 4 cptr prin brea sendcmd duty index if duty index duty index t time NULL tmp t do while A 7 tf Kr tf Ky tf Ky artt KE Ki EnH tf Ky on 0 t time NULL while kbhit t lt tmp 300 amp amp D 10 n Duty Cycle D 25 n Duty Cycle D 50 n Duty Cycle D 75 n Duty Cycle D 90 n Duty Cycle set duty cycle set set set set set to TONN EG 25 n to 50 n to 75 n to 90 n send duty command increment index time delay loop kbhit Model 205 PWM Controller User s Manual a getch cptr S n disable output sendcmd printf n nEnd demo program n exit 0 sendcmd define COM
28. easured Frequency Counter will be able to measure the output frequencies Some DMM s have frequency measurement capability Document No 00046 08 Rev C DMM setting the DMM to measure DC Volts will provide some average value of voltage that will allow you to conclude that the PWM Output is not stuck high or low Changing the duty cycle should change the DMM value displayed LED and resistor placing an LED with a current limit resistor on the output will provide an easy diagnostic tool The LED should visibly flash up to ap proximately 25 Hz A variance in intensity should be discernible at higher frequencies by varying the duty cycle Note that when measuring the output using a scope frequency counter or DMM the signal is present on the OUTPUT terminal and is referenced to the power supply ground or INPUT terminal In conclusion do not attempt to service the PWM Controller internally The methods provided above give a visual indication of operation of the unit This indication is intended to isolate problems with your application of the PWM Controller to the unit itself or the system connection 5 4 Software Upgrades Updates As described in section 4 1 the PWM Controller has field programmable mi crocomputer based circuitry and software Applied Processor and Measure ment Inc is committed to supplying a high quality product and will issue new software releases which will enhance capability and mainta
29. ed by misuse For reference record the Model No and Serial No of your unit in the spaces provided below PWM Controller Model Serial Number 5 2 Service WARNING OTHER THAN FUSE REPLACEMENT OR DIODE JUMPERING THERE ARE NO USER SERVICEABLE PARTS INTERNAL TO THE PWM CON TROLLER DO NOT ATTEMPT TO SERVICE THE UNIT COMPONENTS INTERNAL TO THE PWM CONTROLLER ARE STATIC SENSITIVE AND MAY BE DAMAGED WITHOUT PROPER HANDLING The PWM Controller requires no maintenance or calibration If you detect a malfunction with your unit you must contact Applied Processor and Measurement Inc to obtain a Return Authorization RA Number You must obtain an RA number for either warranty or non warranty service This number must appear on the outside of a suitable shipping carton or on the packing list Applied Processor and Measurement Inc will repair or replace the unit at its option If the return is for non warranty repair you will be noti fied of any applicable charges prior to work being performed Please refer to our website for further information and to contact us for returns servicing 5 1 Model 205 PWM Controller User s Manual Applied Processor and Measurement Inc may be contacted as follows Applied Processor and Measurement Inc www appliedprocessor com cust_support html Phone 716 741 1141 FAX 716 741 1142 E mail support appliedprocessor com 5 3 Diagnostics Currently there are no self diagnostic to
30. er For example the duty cycle may be varied to any value between 0 0 and 100 0 inclusive Pressing the UP pushbutton when the value of the duty cycle is at 100 0 will no longer change the value This is true for any maximum or minimum value for fre quency and duty cycle When using the UP or DOWN pushbuttons to change the polarity the controller simply cycles through the values avail able H or L When the cursor is in the status position and the mode is OFF the UP pushbutton is used to enter Mn mode DOWN to enter Ad then An When operating in either Mn or An mode either pushbutton UP or DOWN will cause the controller to return to the off state The pushbutton interface may be disabled via the remote port or by config uring the PWM Controller with the pushbutton interface to be disabled This is useful in applications where the PWM Controller is used in analog or re mote control and it is desirable to prevent unwanted key presses by unau thorized personnel See section 4 3 2 for the proper remote command and section 4 6 on configuring the PWM Controller with the pushbutton interface disabled 4 3 2 Remote RS 232 Interface The PWM Controller possesses an RS 232 port for remote computer con trol All operational features are accessible via the RS 232 port using ASCII character based commands This allows the PWM Controller to be com manded via a computer executing a terminal emulation program or custom software or via a
31. es Table 4 4 2 Duty Cycle vs Analog Input V3 x Compatibility 4 16 Document No 00046 08 Rev C 250 Hz Range 500 Hz Range 2500 Hz Range Table 4 4 3 Frequency vs Analog Input V2 x Compatibility 200 Hz Range 400 Hz Range 5 000V 200 Hz 400 Hz Table 4 4 4 Frequency vs Analog Input V1 x Compatibility Table 4 4 5 Duty Cycle vs Analog Input V2 x and V1 x Compatibility 4 17 Model 205 PWM Controller User s Manual When using the Analog Input control feature be sure to operate the inputs within the specified limits for the analog inputs as described in Section 2 0 The system commanding these inputs should not exceed the range of 0 0 V to 5 0 V While the inputs are protected command signals over 5 0 V may damage the PWM Controller internal A D converter or the signal source Note that 10 0 V single ended and 5 0V differential input options are available The analog control input selection may be disabled via the remote port or by configuring the PWM Controller with the analog input function to be disabled This is useful in applications where the PWM Controller is used strictly in manual mode where only the Run Mn and Off modes are required In situa tions where manual control is used an accidental key press from the Off mode may select unwanted analog input settings for frequency and duty cycle due to the fact that the analog inputs are not connected Disabling the analog input feature
32. for start up mode will be Run Manual and Off Similarly if Ad is chosen as a start up mode the start up duty cycle menu item will not be displayed for set ting Adjust the setting by using the UP and DOWN pushbuttons press SELECT when adjustment is complete This will cause the menu to go to the next pa rameter to be set 4 21 Model 205 PWM Controller User s Manual After completion of the menu list the final choice will be to save the settings and exit save the default factory settings and exit or exit without saving The default settings are shown above Use the UP and DOWN pushbuttons to display the choice and press SELECT to complete the configuration After completion of the menu sequence the start up screen shall be displayed and the PWM Controller will operate with the reconfigured settings Note that the start up configuration menu is accessible by holding down the SELECT key even when the pushbutton interface is disabled using a previous configuration setting It is recommended that after configuration the user re verify the power up settings prior to connection to the output device in order insure the settings and prevent any possible damage to the device under control 4 22 Document No 00046 08 Rev C 5 0 Warranty and Service 5 1 Warranty The Model 205 PWM Controller is warranted for 90 days from the time of pur chase This includes workmanship and manufacturer defects It does not include failures caus
33. ge from the normal pushbutton user interface In order to set all parameters from the pushbutton interface the start up menu must be used To configure during normal operation power on the PWM Controller wait for the initial messages and let the system start up If you are doing this for the first time the system will initialize to the factory default settings shown above Adjust the frequency duty cycle and polarity to the desired settings using either the front panel interface or the RS 232 remote commands Lastly set the desired operational mode Note that the mode selected shall be the op erational mode that the PWM Controller will use on subsequent power up conditions Normal rules of operational precedence apply For example if the An Analog Input operational mode is selected the PWM Controller shall power on and immediately measure the frequency and duty cycle analog inputs and set the output parameters accordingly 4 20 Document No 00046 08 Rev C The configuration can now be saved such that the PWM Controller will power on in this state for all subsequent power cycles until re configured by the user The settings are stored in the PWM Controller internal FLASH memory and may be reprogrammed at any time using this procedure The parameters can be saved by using one of two methods Using the front panel interface place the cursor on the Stat field using the SELECT pushbutton Simultaneously press the UP and DOWN pushbut
34. gh the load to ground The PWM Controller actuates the load in this manner using the MOSFET as a low side control element and is referred to in this manual as low polarity Operational capabilities within the PWM Controller include the ability to set the PWM Output polarity to either low or high Observing the voltage from the negative terminal of the control output to ground when the load is ener gized the voltage measured will be zero Conversely when the load is not energized the supply voltage will be measured across the output This signal state and the action of the load in this manner occurs when the polar ity of the PWM Controller is set to low Setting the polarity to high will re verse the action of the PWM Output Document No 00046 08 Rev C Consider the signal shown in figure 4 1 1 1 The figure illustrates a 10 Hz PWM signal Using the above discussion of polarity the signal shown represents a 80 duty cycle PWM signal with low polarity or 20 duty cycle at high polarity When setting the PWM Controller to a specific duty cycle consider the polarity setting and the effect on the load device under control 80 msec 100 msec Figure 4 1 1 1 PWM Controller Polarity Example 4 2 PWM Controller Operation Operational Modes The PWM Controller operates in one of four modes Run or Manual Mn Analog Input Freq and Duty An Analog Input Duty Ad or Off This is displayed
35. gn on the output will be placed in the non engaged state based on the configured polarity setting of the unit After sign on the PWM Output will begin operating at the configured settings see section 4 6 on Configura tion After the sign on message is complete the LCD shall display the operational screen The main operational screen for default factory configu ration is shown below Freq Duty Stat 00001 0 0 L Of the main operational screen format can be represented as follows FreqssDutyssStat XXXXXSYYY YSPd2Z 4 5 Model 205 PWM Controller User s Manual with the display fields defined as follows XXXXX frequency 1 to 25000 Hz adjust 100 s 10 s and 1 splace YYY Y duty cycle 0 0 to 100 0 adjust 1 s and 0 1 s place P duty cycle polarity H or L d digital input control state d e or blank ZZ operational mode Mn An Ad or Of s space cursor To change any value displayed on the LCD except the digital input control state which reports only use the SELECT pushbutton to locate the cursor on the field to be changed then use the UP or DOWN pushbuttons to change the current value The pushbuttons possess a fast increment or decrement feature that begins a few seconds after holding the button down This allows large changes in the frequency or duty cycle to be accom plished quickly The description in the preceding paragraph provides the current values or ranges available for each paramet
36. ich uses a motor to drive a process In this example the motor is the device being developed and it requires a PWM signal at 100 Hz for commanding the motor speed That is the speed is directly proportional to the input signal duty cycle The motor is to be controlled by a PLC Programmable Logic Controller which is also used to monitor the process The PLC must monitor the process and control the Document No 00046 08 Rev C motor speed accordingly The PC shown in the system provides a user interface for the test operator and stores the test data and generates re ports This scenario represents a common development equipment archi tecture which may be found in industry today The PWM Controller supplies the PWM signal to the motor in the process Two 0 to 20 mA output channels on the PLC which are converted to volt age using the 250 ohm resistor provide the control signal to the PWM Con troller Note that one output is fixed to 2 000 V to command a fixed fre quency output at 100 Hz V1 x compatibility mode 200Hz range settings This could also be done by hardwiring a fixed resistor combination from the power supply to the frequency input Alternately the PWM Controller may also be configured to the Adt opera tional mode with a fixed output frequency of 100 Hz In this case only one analog output is required to control the PWM Controller Finally the PWM Controller does not possess isolated analog input amplifi ers As in any
37. in the software When purchasing the PWM Controller your unit will be automatically regis tered This registration will allow you to receive notices and pricing informa tion on software releases and new software versions containing operational enhancements and new features The PWM Controller software is capable of being field upgraded connection to a PC is required Releases for bug fixes will be provided at no charge Consult the support page at www appliedprocessor com for information on new software releases and how to support your unit Model 205 PWM Controller User s Manual 5 5 Customization Since the PWM Controller functionality is software controlled and the control ler may be field upgraded the unit may be customized to suit your application Call and discuss your requirements with one of our engineers Our engineer ing staff has extensive experience in test applications and embedded system applications Applied Processor and Measurement Inc will respond quickly with a quotation upon your request Applied Processor and Measurement Inc engineers have been designing microprocessor based instrumentation and embedded control systems since 1980 We welcome inquiries on custom designs variations on this design as well as customized software for your application Call and discuss your engi neering needs with one of our engineers Document No 00046 08 Rev C Appendix A Application Examples Below are listed only a few
38. l 205 PWM Controller User s Manual Configuration may be accomplished using either the front panel or the RS 232 remote port To change the power on settings of the PWM Controller connect the unit to a power source as shown in the installation instructions WARNING IT IS RECOMMENDED NOT TO HAVE THE OUTPUT DEVICE LOAD CONNECTED DURING CONFIGURATION IF YOUR SYSTEM CANNOT TOLERATE A FULL ON OR OFF OUTPUT STATE THE LOAD SHOULD NOT BE CONNECTED DURING CONFIGURATION DURING THE INTER NAL PROGRAMMING OF THE CONFIGURATION SETTINGS THE PWM CONTROLLER WILL DE ENERGIZE THE OUTPUT TO THE CURRENTLY CONFIGURED POLARITY IF YOUR SYSTEM CANNOT TOLERATE THIS DISCONNECT IT AND RE CONNECT AFTER CONFIGURATION IS COM PLETE There are two methods to configure the PWM Controller from the front panel interface One method sets the configuration parameters while operating the other accesses a menu driven start up sequence which is able to configure all aspects of the PWM Controller The configuration may also be saved via the CFN command on the remote port This is also performed during normal op eration Note that enabling and disabling of the pushbutton and analog inter faces and setting the operating frequency range may only be configured from the menu driven sequence and the remote port command for configuration This is because there is no way to change the enable and disable of the pushbuttons and analog interfaces or the operating frequency ran
39. l software vrs to 1 Command Command Help Syntax H lt CR gt Parameters none Description Use the H command to display all the remote commands of the PWM controller A summary as shown in table 4 3 2 1 will be displayed Example H lt CR gt display command summary Command Information on System Syntax I lt CR gt Parameters none Description Use the command to provide information on the PWM Controller model number serial number and software version number This information is useful in service calls to Applied Processor and Measurement Inc and maintaining your unit with respect to software upgrades See sec tion 5 4 IS may also be used version 2 or 1 software command Example I lt CR gt reports the system information 2 lines PWMC205 rev 3 0 c 2007 APM Inc Serial Number 03110 4 11 Model 205 PWM Controller User s Manual Command Enable Disable the Pushbutton Interface Syntax K x lt CR gt Parameters x where 0 disable 1 enable Description Use the K command to remotely enable or disable the front panel pushbutton operation This can be used to prevent unwanted changes of the PWM Controller settings when operating in the remote or analog opera tion modes When disabled any pushbutton presses are ignored by the PWM Controller Example K 0 lt CR gt locks out the pushbutton interface Command Lockout Status Syntax L lt CR gt Parameters none Description Use the L comma
40. le and mode of operation e remote operation via RS 232 interface commands set frequency and duty cycle readout current settings enable disable output controller configuration 1 2 Document No 00046 08 Rev C e analog input control two modes of operation control frequency and duty cycle output with two analog inputs control duty cycle only with one analog input e opto isolated digital input control to enable disable PWM output e configure operation via the pushbutton interface on power up during opera tion and via the RS 232 port menu driven configuration available on PWMC power up e capability to disable analog input operation and pushbutton interface if not used e high reliability single circuit board construction using surface mount tech nology 1 2 Differences Between Model 205 PWM Controller Versions e Frequency of Operation The PWMC 205 software revision 3 x provides for operation of the standard Model 205 PWM Controller up to 25 000 Hz The primary operational frequency range differences between revisions 3 x 2 x and 1 x may be summarized as follows revision 3 x 1 to 1000 Hz 1 Hz steps revision 3 x 1000 to 10000 Hz 50 Hz steps revision 3 x 10000 to 25000 Hz 100 Hz steps revision 2 21 1 to 250 Hz 1 Hz steps revision 2 21 2 to 500 Hz 2 Hz steps revision 2 21 50 to 2500 Hz 50 Hz steps revision 2 0 2 1 1 to 250 Hz 1 Hz steps revision 2 0 2 1 2 to 500 Hz 2 Hz steps revision 1 x 1 to 200 H
41. ler is intended to be used in a laboratory industrial environment It is not intended for use in or in conjunc tion with any medical or life support appliances devices or systems Applied Processor and Measurement Inc assumes no liability from the use of this design in this context Applied Processor and Measurement Inc does not assume any liability for the malfunction of electronic components contained in any of its products nor any damage incurred from the improper use of the product to the user prod uct or any connecting equipment GROUND THE SYSTEM Even though the Pulse Width Modulation Controller requires an external DC source care should be taken that the total system is properly grounded Use only power supplies that have three conductor AC power cable with the grounding wire properly connected to an electrical safety ground This will minimize shock hazard DC POWER ONLY The Pulse Width Modulation Controller requires an external DC source of 9V DC to 24V DC Do not connect the Pulse Width Modulation Controller directly to 120 or 240 V AC DO NOT SERVICE THE UNIT Do not attempt to service the unit NEVER open the unit while it is operating Do not attempt to substitute parts or modify the system internally iv Document No 00046 08 Rev C Table Of Contents 1 0 ItrOAU CH ON eioi tidade anteaters 1 1 1 1 Featuresn muinuaskume a ies 1 2 1 2 Differences Between Model 205 PWM Controller Verslonsiugaxuaradu
42. ller may be directly connected to the PC via the serial port The control software would need to interface with the PC COM port and send the PWM Controller the proper ASCII commands for setting the frequency and duty cycle see the operations section of this manual A 4 A 5 Document No 00046 08 Rev C PCMCIA Card Analog Inputs Analog Outputs COM Port Analog In Control RS 232 Intf PWM Signal PWM Controller Figure A 2 1 PWM Controller PC PCMCIA Interface Example Model 205 PWM Controller User s Manual A 3 Commanding the PWM Controller with PC Software The following example C code commands the PWM Controller via the COM port ona PC The example program demonstrates how a PC may commu nicate with the PWM Controller remote port command set The software commands a test sequence of 5 different duty cycles at a fixed PWM fre quency a potential validation test on a solenoid The duty cycle is changed every 5 minutes Zx 7 DEMOL C A ae Description PWM Controller Demo Software Kl This program controls the PWMC via a PC SIO port A sample prgm changes the controller duty cycle for a durability test every 5 minutes kor This program assumes the use of PC COM2 port ged E at 9600 N 8 1 K E Ef JEG E include lt stdio h gt include lt dos h gt include lt conio h gt inclu
43. m applications The analog inputs may also be ordered for 5V or 10V input capability See our website for order numbers e External Enable Input The analog input connector provides an optically isolated digital input to enable or disable the PWM output This feature is configurable so that this function may be used or disabled The Model 205 PWM Controller may be operated in the same manner as the previous Model 205 and the Model 200 01 All remote commands analog input operation and the pushbutton interface are completely compatible No changes are required for systems in place using the V2 x Model 205 or the V1 x Model 200 01 in either remote operation or analog input operation when transitioning to the new version 3 x Model 205 Document No 00046 08 Rev C 1 3 Applications The Model 205 PWM Controller was specifically designed for product devel opment activities and durability and validation testing of electromechanical devices requiring a PWM control signal The PWM Controller may also be used to provide a PWM signal for life testing of solenoid valves actuators or relays The PWM Controller may also serve as a signal conditioning element for com puter control systems since it may be commanded by either analog signals or an RS 232 command Application examples are provided in the Appendix Contact Applied Processor and Measurement Inc for applications assistance and regarding variations or customizations of the Model 205
44. mote port communication parameters are set for the following Baud Rate 9600 bps Parity none Data Bits 8 Stop Bits 1 Flow Control none Note that this port is not isolated from the controller input ground the Input terminal 3 4 Analog Input Connections WARNING CONSULT THE SPECIFICATIONS FOR SIGNAL LIMITS ON THE ANA LOG INPUT PORT ALTHOUGH THE PWM CONTROLLER ANALOG INPUTS ARE PROTECTED APPLYING VOLTAGES TO THESE INPUTS BEYOND THE RATINGS SPECIFIED MAY DAMAGE THE PWM CON TROLLER Analog input control allows control of the PWM output frequency and duty cycle or duty cycle only from the analog input port on the upper left side of the unit The pinout of this port is shown in table 3 4 1 In order to maintain compatibility with future versions of the PWM Controller make no connec tions to the pins labeled as Do Not Connect The port pins are connected via a standard commercially available 8 pin insulation displacement style connector AMP part number 3 640440 8 8 pin discrete insulation dis placement connector housing A mating plug is supplied with the unit when purchased and is installed in the analog input port at the factory If analog input mode for PWM control is not required for your application the analog input function can be disabled when configuring the unit 3 10 Document No 00046 08 Rev C Pin Signal Signal Number Model PWMC 205 Model PWMC 205 DF only PGND Duty Cycle Control 7 T
45. n to frequency and duty cycle In An mode the front panel pushbuttons and the remote port RS 232 control of frequency and duty cycle are disabled Changes may be made to the duty cycle polarity and the mode of operation from either the pushbuttons or the remote port Off Of The PWM Output is disabled the values of the frequency duty cycle and duty cycle polarity are displayed and are controlled by either the pushbut tons or the remote port RS 232 or the analog inputs However these val ues are not translated to the output until the Mn Ad or An modes are en abled The output state is set in accordance with the current polarity set ting Note that when the Analog Input modes are not to be used they may be disabled through configuration of the PWM Controller In this case only the Manual and Off modes will be available on the LCD pushbutton interface and via the remote interface 4 2 1 PWM Controller Operation Frequency Setting The PWM Controller is able to operate from 1 to 25000 Hz The resolution of the setting is controlled as follows 1 to 1000 Hz in 1 Hz steps 1000 to 10000 Hz in 50 Hz steps 10000 to 25000 Hz in 100 Hz steps The LCD pushbutton interface or the remote port serial port interface will automatically coerce the value to the nearest capable setting Analog input resolution settings are configured separately See section 4 4 for information on analog input control of the operating frequency
46. nd to provide the current status of the PWM Controller with respect to the state of the pushbutton analog and digi tal input interfaces Example L lt CR gt report pushbutton and analog interface lock status Keypad Operation Enabled PWM Controller response 3 lines Analog Input Modes Disabled Digital Input Mode None Command Set the Digital Input Mode Syntax M x lt CR gt Parameters x where 0 none 1 enable disable Description Use the M command to remotely set the digital input opera tional mode Setting the mode to 0 disables the digital input feature Setting the mode to 1 sets the digital input mode to enable disable When in en able disable mode the digital input must be asserted see section 4 3 3 to allow the controller to PWM the output When the digital input is not asserted the output will be disabled The digital input mode setting is reported via the L command with no parameters Example M 1 lt CR gt set the digital input mode to enable disable Command Set Output Polarity Syntax P x lt CR gt Parameters x where x 0 or 1 Description The P command sets the PWM Controller output polarity Use the parameter 0 to set the polarity to active low use a 1 for active high Sending commands to a PWM Controller that is already operating in that polarity will have no effect Example P 1 lt CR gt will set active high polarity 4 12 Document No 00046 08 Rev C
47. nge Output Freq Voltage Input 0 016 10 Hz 2500 Hz range Output Duty Cycle Voltage Input 0 020 0 5 Output Analog Control Equations version 1 x software compatibility Output Freq Voltage Input 0 020 1 Hz 200 Hz range Output Freq Voltage Input 0 020 2 Hz 400 Hz range Output Duty Cycle Voltage Input 0 020 0 5 4 15 Model 205 PWM Controller User s Manual Note that the control signals are limited by the operating specifications of the controller for frequency resolution That is the frequency output is limited to operating from 1 to 1000 Hz with a resolution of 1 Hz 1000 to 10000 Hz 50 Hz resolution and 10000 to 25000 Hz with 100 Hz resolution The example tables below quantify these values and the corresponding analog control sig nal values Note that the values of frequency and duty cycle saturate over the maximum values Also note that for V2 x and V1 x compatibility modes the duty cycle resolution is fixed to 0 5 Analog Frequency Frequency Frequency Frequency Frequency Voltage Setting Setting Setting Setting Setting 250 Hz 500 Hz 1000 Hz 10000 Hz 25000 Hz Range Range Range Range Range 100 Hz 0 020V 100 Hz 0 040V TOO Hz 200 Hz 500 Hz 5000 Hz 10000 Hz 15000 Hz 20000 Hz 5 000V 250 Hz 500 Hz 1000 Hz 10000 Hz 250000 Hz Table 4 4 1 Frequency vs Analog Input V3 x Compatibility Duty Cycle Duty Cycle Duty Cycle Duty Cycle 1 0 res 0 5 res 0 2 res 0 1 r
48. ols within the PWM Controller How ever there are steps that may be taken to diagnose problems within the unit and verify its operation as stand alone as opposed to operating in your appli cation If the unit is typically operated using the front panel interface connect the serial port to a PC as described in section 3 3 It is possible that the LCD has failed in which case the remote port interface may be used to operate the controller until the unit may be serviced If the unit is still not operable obser vation of the messages on the remote port may assist in diagnosing the unit Basically the PWM Controller is a signal generator therefore any test equip ment used to detect or measure signals may be used to check the PWM Out put If it appears that you are still in control of your PWM Controller but you are in doubt of the PWM Output simulate your load by connecting a resistor across the output as described in section 3 0 Connect your test equipment across the negative terminal on the PWM Output to ground the negative ter minal on the power input Depending on the level of diagnosis desired any of the following methods may be used to determine whether the PWM Con troller is generating an output signal Check the Output Fuse the output fuse may have been blown See section 3 1 on replacing the internal fuse Oscilloscope best method of observing the output The change in frequency and duty cycle may be observed and m
49. oltage and or cur rent MOSFET or a high amperage power module This configuration al lows the current and voltage ratings of the PWM Controller to be extended to any rating based on the external components available Remember that adding another N type MOSFET or power module in the circuit adds an other level of inversion Use the polarity function built in to the PWM Con troller to account for the desired signal level For more information and applications on using the PWM Controller as a signal generator signal conditioner for control systems see Appendix A Model 205 PWM Controller User s Manual 3 1 Fusing WARNING BE SURE TO FUSE THE PWM CONTROLLER PROPERLY IN ORDER TO AVOID POSSIBLE DAMAGE TO THE PWM CONTROLLER TO YOUR LOAD DEVICE OR SYSTEM UNDER CONTROL WHEN CHANG ING THE FUSE OR REMOVING THE BACK COVER BE SURE THAT THE PWM CONTROLLER IS NOT CONNECTED TO ANY POWER SOURCE The PWM Controller contains an internal fuse for device load protection and for the PWM Controller output MOSFET electronics itself The input fuse is connected in series with the load and the output Power MOSFET see the PWM Controller Block Diagram in figure 4 1 1 for details on the fuse connection therefore the fuse will protect both the PWM output drive circuitry as well as the device load under test Fuse holder clips are provided on the back of the PWM controller main cir cuit board To replace the fuse in the unit remove the back cover N
50. ote that the circuit board need not be removed from the top of the enclosure the fuse is completely accessible from the back of the unit by simply remov ing the back cover The PWM Controller contains static sensitive circuitry be sure to handle the unit so as to avoid touching the circuitry on the front of the circuit board and pins on the back of the circuit board The fuse is a standard 3AG size glass fuse A 3AG type 4 Amp fuse is installed in the unit from the factory Littelfuse part number 0312004 HXP Be sure to fuse the PWM Controller properly based on the current draw of the device load under test Refer to table 3 1 1 for maximum recommended fuse ratings for different voltages Operating Voltage Maximum Fuse Rec ommended Table 3 1 1 PWM Controller Maximum Recommended Output Fuse Ratings 3 8 Document No 00046 08 Rev C 3 2 Internal Diode The PWM Controller possesses an internal S2BA 13 diode across the out put terminals to suppress inductive current kick back from the load under test see the PWM Controller Block Diagram in figure 4 1 1 for details on the diode connection The S2BA 13 is a general purpose diode similar to the 1N4001 and suits most needs when working with inductive loads such as valve solenoids and relays If your application uses another type of di ode the internal diode may be easily removed from the circuit and your diode may be installed on the PWM Controller externally across the and
51. ote that commands from any source remote port or pushbuttons that change the mode of operation are always allowable except when the pushbutton interface is disabled Only commands that change the frequency and the duty cycle are subject to the rules of precedence Finally when enabled the digital input enable disable state overrules the output state 4 6 PWM Controller Configuration When the PWM Controller is powered on the parameters of PWM output are initialized to settings contained within the reprogrammable FLASH configura tion memory of the PWM Controller microprocessor system The user is able to configure these initial power up settings This enables the PWM Controller to be set up for operation in a fixed environment without manual operator interaction such as a test system using the PWM Controller in one of the ana log input modes Factory default settings for the PWM parameters are as follows Output frequency 1 Hz Output duty cycle 0 Output polarity low Mode output off Pushbutton Interface enabled Analog input modes enabled Digital input mode none Analog version compatibility V3 x Analog Control Freq range 250 Hz Analog Control Duty resolution 0 5 The factory default settings guarantee a non energized condition on the out put assuming an active low polarity If your device is opposite polarity the default settings may be changed to insure a non energized condition for that device 4 19 Mode
52. power supply for the PWM Controller is avoided Note that the PC is also shown connected to the PWM Controller If 0 to 20 mA outputs are not available in the PLC the PC may be used to command the PWM Controller In that scenario the PC would need to receive the speed command information from the PLC translate it into a PWM Control ler command for example D 30 lt CR gt for a 30 0 duty cycle and trans mit the command to the PWM Controller A 2 Using the PWM Controller with a Laptop PC and a PCMCIA Data Acquisition Card The example below illustrates how a PC may be directly interfaced to the PWM Controller A currently popular architecture for laboratory benchtop and portable data acquisition and control systems is a laptop PC which uses a multifunction PCMCIA data acquisition card Because of the laptop PC and the versatility of the data acquisition card analog and digital I O the configuration yields a very powerful yet compact and portable controller and or data system Figure A 2 1 shows a PC with a data acquisition card which drives the PWM Controller In this example the PWM Controller drives a device re quiring a PWM signal for control The PC through the PCMCIA card moni tors the system for example temperatures pressures etc with its analog inputs and provides analog outputs for frequency and duty cycle control Software drivers usually in C are provided by the PCMCIA card supplier Note that the PWM Contro
53. quency operating range when under analog control See section 4 4 for the analog to frequency conversion factors that are based on the range setting Note that the value that can be set is dependent on the software compatibility setting that is set using the GV command The G with no parameters will report the current frequency range setting and version setting Example G 500 lt CR gt sets the analog freq range to 500 Hz G 25000 lt CR gt sets the analog freq range to 25000 Hz 4 10 Document No 00046 08 Rev C Command Set the Analog Frequency Control Range Version Syntax GV x lt CR gt Parameters x where x 1 2 or 3 for V3 x V2 x or V1 x software setting Description Use the GV command to remotely set the pulse output fre quency operating range software version compatibility setting when under analog control See section 4 4 for the analog to frequency conversion fac tors that are based on the range setting and the software version setting The software version setting is provided to allow for backward compatibility of the Model 205 for analog control installations that have used units with version 2 of version 1 software and hardware It is recommended that the software version is set prior to setting the range G command Executing the GV com mand resets the range to the minimum value for that setting Use the G com mand with no parameters to report the version setting Example GV 1 lt CR gt sets the analog contro
54. s and the integral LCD the output frequency and duty cycle may be adjusted digitally from 1 to 25 000 Hz with a resolution of 0 1 duty cycle The PWM Controller may also be controlled via an RS 232 port Single letter ASCII based commands allow the frequency and duty cycle to be set and displayed This capability allows the PWM Controller to be controlled by a host computer e g a PC compatible or PLC The PWM Controller output is an open drain power MOSFET output This provides low side control of the load to be pulse width modulated An external DC power source must be provided which may be used to power both the load and the controller This provides maximum flexibility since the load volt age can be set by the user using any variable bench top power supply or it can derive power directly from the system under control provided the control ler is operated within the rated specifications An analog input control feature is also available for the PWM Controller This input allows the user to control the output frequency and duty cycle with ana log control signals such as 0 to 5V or 0 to 20 mA across a 250 ohm load An external control system for example a PC with data acquisition cards a laptop PC with a PCMCIA data acquisition card or a PLC could provide ana log outputs to the PWM Controller in order to control a PWM device In this manner the PWM Controller is a signal conditioning element for the host computer and or control sys
55. tem The operation of the PWM Controller is highly configurable User program mable configuration options are available to set the power up state of the PWM Controller and it s operational state with respect to analog input opera tion output frequency range and the enabling and disabling of features 1 1 Model 205 PWM Controller User s Manual 1 1 Features The following is a summary of the feature set of the Applied Processor and Measurement Inc Model 205 PWM Controller e user computer adjustable pulse width modulated output square wave with the following characteristics 1 to 25 000 Hz operating frequency 0 to 100 duty cycle e frequency adjustable as follows 1 to 1000 Hz in 1 Hz steps 1000 to 10000 Hz in 50 Hz steps 10000 to 25000 Hz in 100 Hz steps e duty cycle adjustable in 0 1 steps e duty cycle polarity control e PWM output provides low side load control e Power MOSFET output PWM output sinks up to 4 amps at 12 volts e internally fused output standard 3AG glass fuse easily replaced e controller operates from same power source that powers the load an ex ternal power source 9V to 24V DC must be supplied e input power reversal protection circuitry protected by resettable polyfuse e built in user interface for adjustment of frequency and duty cycle 3 switches and LCD allows precision digital control of the output parameters e integral LCD 2 line by 16 character displays current frequency duty cyc
56. that this command set ting is only valid when version 3 software is set In version 2 or 1 compatibility modes the analog duty cycle control resolution is fixed at 0 5 for backwards compatibility The percent sign is not required and should not be used Use the V command with no parameters to report the current setting Example V 0 2 lt CR gt will set the output duty resolution to 0 2 when in analog control mode 4 13 Model 205 PWM Controller User s Manual 4 3 3 PWM Controller Operation Digital Input Control The PWM Controller allows for remote control of the PWM output via an opto isolated digital input This allows for the output to be enabled or disabled by an external device such as a PLC The digital input control is connected via 2 pins of the 8 pin connector on the front left side of the unit For the connector pinout see section 3 4 The digital input operational feature must be set on or off using the M com mand or the start up configuration menu see section 4 6 When this fea ture is enabled the output is enabled or disabled based on the state of the digital input Power 5 to 24V DC applied to the digital input will enable the PWM output When no power is applied to the digital input the PWM output is stopped The PWM output is enabled or disabled within 5 msec of a digital input state change and is asynchronous to the current PWM cycle i e once the digital input is de asserted the output will be
57. tons until the LCD displays Cf in the status field Cf will be displayed briefly and the PWM Controller will return to the operational mode that it was in prior to the configuration command The pa rameters may also be saved using the remote command interface RS 232 and typing CFN lt Enter gt The display will also show Cf on the display using this method as well During configuration the PWM controller will de energize the output to the currently selected polarity The PWM controller is now reconfigured A start up sequence is also available via the pushbutton user interface that allows setting of all the PWM Controller parameters in the list above This is the recommended method for PWM controller configuration In order to access the menu hold down the SELECT pushbutton while apply ing power to the PWM Controller The start up messages will be displayed followed by a message prompting to release the SELECT pushbutton to begin configuration All settings will be individually displayed for adjustment in the following order Enable Analog Input Analog Control Version Compatibility Analog Control Frequency Range Step Analog Control Duty Cycle Resolution Start up Mode Start up Frequency Start up Duty Cycle Start up Output Polarity Digital Input Mode Keypad Enable Note that settings in the beginning shall determine whether later displays are accessed For example if Analog Inputs are disabled the only choices
58. ust be rated to accept the load under control Note that the power supply negative output terminal is commoned at the PWM Controller This connection must be made if the power supply outputs are isolated Some laboratory power supplies have one common ground for 12V 12V and 5V outputs that are produced from the same supply and this connection may not be required Consult the manual from the power sup ply that you are using in this application to check if it is required to common the negative terminals externally Additionally applying the common connec tion at the PWM controller will assist in providing a return path for the power being dumped by the load when switching This will help to keep the power for the PWM Controller cleaner especially when the power supply is a greater distance from the load and the PWM controller Document No 00046 08 Rev C Figure 3 0 3 illustrates another variation of the dual supply configuration Any 12V source even an inexpensive unregulated AC to DC adapter may be used for the PWM Controller power In this case the load power is ob tained from an external power supply or an external source where the de vice under control is applied Note that the common connection at the PWM Controller is still required This is the recommended configuration for applications requiring dual supply connections Host Computer PC PWM Controller Power Supply RS 232 Input Output 5 to 50 V DC External
59. vides the load and the signal can be obtained from the controller as shown in the figure This signal can then be supplied to any device requir ing a PWM square wave for control Be sure to apply the correct voltage level to your device The advantage to using the PWM Controller as a signal conditioner is in the methods that are provided to command the PWM Controller The PWM Con troller has the ability to accept analog control signals or RS 232 ASCII charac ter based commands Typically in data acquisition and control systems ana log outputs voltage or 0 to 20 mA or serial ports are usually available These systems may also possess digital I O or possible timer counter facili ties but these resources may not be able to easily produce PWM signals A 1 Model 205 PWM Controller User s Manual An example of a data acquisition and control system application is shown in figure A 1 1 This example illustrates both types of connections between the control system and the PWM Controller both are not required PROGRAMMABLE LOGIC CONTROLLER PLC INTF CARD SERIAL PORT 0TO20 mA OUTPUTS 250 OHMS EA VW iN OUT FREQ DUTY ANALOG INPUTS PWM CONTROLLER PROCESS Figure A 1 1 PWM Controller Signal Conditioning Example In this application a control system is constructed wh
60. wer supply The power supply sources current for both the PWM Controller and the device under control Host Computer PC PWM Controller Power Supply RS 232 Input Output 9 to 24 V DC Device Under Control Figure 3 0 1 PWM Controller Single Supply Connection This figure illustrates the low side drive connection of the PWM Controller Also note that because of the open drain output an external connection must be added between the positive terminal for the power input and the posi tive terminal on the output of PWM Controller 3 1 Model 205 PWM Controller User s Manual Figure 3 0 2 shows the recommended connection for a dual power supply connection This configuration would be used for a load that is under test whose operational voltage is not in the PWM Controller operating range of 9V to 24V DC The PWM Controller must be supplied 9V to 24V DC for its oper ating power The output of the unit may operate at any voltage from 5V to 50V within the recommended power specifications see Section 2 Host Computer PC PWM Controller Power Supply RS 232 Input Output 12V DC 5V DC Poi Device Under Control Figure 3 0 2 PWM Controller Dual Supply Connection In the dual supply configuration example above the power supply has a 12 V and a 5 V output Only 75 mA of 12V is required to supply the PWM Con troller whereas the 5V supply m
61. will prevent this situation See section 4 3 2 for the proper re mote command and section 4 6 on configuring the PWM Controller with the analog inputs disabled 4 5 PWM Controller Operation Precedence The PWM Controller software uses rules of precedence with respect to its modes of operation Dependent on the operational mode selected the rules of precedence within the PWM Controller software govern how the controls affect the PWM Controller output The following paragraphs outline the operation of the PWM Controller with respect to its current mode of operation Mode Run Manual Controls Effected no restrictions Summary commands to change mode frequency duty cycle and polarity via the pushbuttons or the RS 232 interface are accepted and implemented im mediately on the output Mode An or Ad either analog input mode Controls Effected Front Panel Pushbuttons RS 232 Summary changes to the frequency and duty cycle via the pushbuttons and remote port RS 232 are disabled analog inputs translate to action on the frequency and duty cycle of the output based on the analog input mode se lected mode and polarity can be controlled with RS 232 and or pushbuttons 4 18 Document No 00046 08 Rev C Mode Off Controls Effected no restrictions Summary values of frequency duty cycle and polarity may be changed from any source output does not reflect it until re enabled by entering Run Mn Ad or An mode N
62. y and duty cycle inputs Do not exceed 25mA at 5V 3 12 Document No 00046 08 Rev C 4 0 Operation This section describes operation of the PWM Controller All operational modes are described pushbutton interface front panel remote RS 232 analog input control and digital input control 4 1 Theory of Operation All operations of the PWM Controller including the generation of the pulse width modulated output signal are controlled by a highly integrated micro computer based design A simplified block diagram of the PWM Controller is shown in figure 4 1 1 FREQUENCY ANALOG CONTROL INPUTS DUTY CYCLE AD CONVERTER RS 232 DRIVER amp RECEIVER MICROCOMPUTER AND FPGA 5V REGULATOR PUSHBUTTONS amp LCD AN SZ2BA 13 Lt OUTPUT JUMPER OUTPUT DRIVER POWER MOSFET Figure 4 1 1 PWM Controller Block Diagram Model 205 PWM Controller User s Manual The PWM Controller output timing is based on a crystal oscillator which drives PWM counter resources internal to the Field Programmable Gate Array FPGA logic The user enters the output parameters into the PWM Controller via the RS 232 port or the pushbutton LCD interface The mi crocontroller calculates signal timings based on these parameters and loads the FPGA PWM counters Note that changes to the frequency and duty cycle are
63. z 1 Hz steps revision 1 x 2 to 400 Hz 2 Hz steps Additionally it is no longer necessary to set the frequency range of operation of the PWM Controller for pushbutton interface control and RS 232 control The frequency may be set to any value from 1 to 25000 the PWM Controller software will coerce to the nearest frequency step based on the ranges given above The G command is now used to set analog input control ranges 1 3 Model 205 PWM Controller User s Manual e Duty Cycle of Operation The PWM Controller has been enhanced to pro vide for 0 1 duty cycle resolution operation in all operational modes e Analog Input Control Analog input control still requires range setting how ever additional ranges are supplied see section 4 4 of this document and the capability to control to higher duty cycle resolution is also provided Duty cycle resolution via the analog input is settable to 1 0 0 5 0 2 and 0 1 Also the analog input port is now controlled by a 0 to 5V analog input Finally version 1 x and 2 x range setting and control compatibility is also pro vided in order to maintain backward compatibility A new Model 205 can be configured and applied to the same test set up as any previous version Model 205 or Model 200 01 e Analog Input Control Options now available The Model 205 PWM Control ler may now be ordered with fully differential analog input ports This elimi nates ground loops in PLC and PC control syste

Model 205 User Manual - Applied Processor and Measurement, Inc.

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