LC220 Logic Controller User Guide
Contents
1. Force Trigger Ind Operator Jind None aj i Notes Apply 14 Channel properties are organized by tabs The tabs that are relevant for a particular timing mode appear automatically when that timing mode is selected For convenience all settings are retained and saved including those for timing modes that are not currently selected Four additional buttons appear next to the tabs Enable restores channel functions following a temporary disable The front panel LED for that channel will glow to indicate the channel s status Disable temporarily disables the channel The channel remains fixed in its quiescent state see Quiescent States below The front panel LED for that channel will be unlit See Running Experiments Channel LEDs Reset reinitializes the internal trigger counters and sweep timing for the current channel This function can be called simultaneously for all channels by pressing the Reset button on the main tool bar Force Trigger lets you simulate a valid input signal for the channel see Channel Properties Logic for more This button which is only available with functions that can be triggered is useful both for troubleshooting your channel settings and implementing software control of experiments You can also force trigger a channel from the LC220 panel See Running Experiments Force Trigger Quiescent states When you disable a channel its input will not chang2. Labomith TOOLS FOR SCIEN LC220 Logic Controller User Guide Documentation for the LC220 Controller and Trig220 Control Software v 1 0 Trig220 software 2004 2005 LabSmith This manual 2004 2005 LabSmith No part of this document may be reproduced or distributed without the consent of LabSmith TABLE OF CONTENTS INTRODUCTION 4 Parts list 4 Specifications 4 Basic functions 5 How you will use the LC220 5 Installing Trig220 Software 5 Setting up the LC220 6 Field upgradeable software 7 Getting help 7 OVERVIEW OF LC220 CONTROLS 8 Inputs and outputs 9 Panel controls 9 TRIG220 SOFTWARE INTERFACE 10 Main screen 10 Time base settings 12 Clock source 12 Clock multiplier 12 Time base 13 General options 13 Disable enable outputs 13 Lock unlock panel 13 CHANNEL PROPERTIES 14 Channel properties screen 14 Quiescent states 15 Logic 16 Logic assignments 17 Experimenting With Channel Logic 18 Timing modes 19 Apply versus Program All Channels 20 Fixed output mode 21 Passive mode Output Input 22 Clocked pulse stream mode 23 Important delay timing considerations 29 Timer mode 34 Dynamically delayed pulse mode 35 Toggled output mode 40 RUNNING EXPERIMENTS 41 Storing and recalling experiment files 41 Panel controls and indicators 41 Channel LEDs 41 Output LED 43 Trigger A and Trigger B 43 Reset 43 GLOSSARY 44 INTRODUCTION The LC220 is a programmable logic and ti
3. mode with a delay and duration of 500 ms each Setup for edge triggering and allow retriggering 38 6 On Channel A s Logic tab select inA not in1 This logic will cause the delayed trigger to pulse 100 ms after the button press On Channel B s Properties window select Dynamically Delayed Pulse mode Set up for scaling by 2 where N 1 and set the Added Delay to 200 us and the duration to 100 ms Allow unlimited retriggering On Channel B s Logic tab select inB outA or not inl This routes the button push signal and the delayed signal to channel B Since you ve made changes to multiple channels click the Program All Settings button Now the test is ready Depress and release the trigger button quickly Channel A will produce a trigger pulse 500 ms later Both the button push and delayed signal will appear on the inputs of Channel B When Channel B receives the button push signal it will begin its count When Channel B receives the delayed pulse from Channel A it will calculate the time difference 500 ms multiply it by 32 16 and subtract the 200 us offset 999 8 ms after receiving the signal from Channel A Channel B will send a 100 ms output pulse 39 Toggled output mode This mode toggles its output state upon every input pulse It functions like a flip flop and is useful for a variety of logical and control purposes The minimum input pulse state duration is 10 ns and the edge to toggle
4. has on the channels depends on the timing mode of the channels The third button Reset causes both channels to have their timing modes reset Again the effect of the reset depends on the channel settings These settings are detailed in the following sections TRIG220 SOFTWARE INTERFACE Trig220 has been designed exclusively for setup and control of the LC220 You ll use Trig220 to set the timing properties and logic for each of the channels and to set up overall properties for the experiment Main screen When you run Trig220 you Il be greeted by the Main screen Wi Trig220 File Edit View Actions Help DSA SB LC220 Logic Controler Channel Channel B r Timing mode m Timing mode Statically delayed pulse y Dynamically delayed pulse X elay Triggering Sweep Trigger logic Scaling Delay Triggering Enable r Added delay can be negative J Enable Operator a us Disable for i Not Int gt Disable r Duration of pulse f 120 ea all eset Ci wih eset l Inverted output pulse from high to low Notes jee NOTE At start up the Main screen will show the default program which sets both channel outputs to a fixed low state 10 From this screen you ll control or access all of Trig220 s functions Most Trig220 functions can be accessed in two ways by selecting an option from a pull down menu or by pressing a button on t
5. upon the current timing mode Time base 5 ns 320 ns Delay range 20 ns to 21 47 s 1 28 us to 1374 s Duration range 7 7 us to 21 47 s 493 us to 1374s Delay Duration 5 ns 320 ns resolution Triggering This tab lets you control how the channel will trigger Channel A Timing mode Statically delayed pulse v Trigger logic Delay Triggering Sweep Normat Skip N triggers N fo C Retrigger N times Automatically reset count sweep f Never C Onini high On int low Check after completing each trigger Enable Disable Trigger on C Input high level trigger Rising input edge trigger Reset Notes Apply Normal The channel can retrigger an unlimited number of times Force Trigger eid 26 Skip N triggers Retrigger N times Trigger on rising input Trigger on input high The channel triggers only after the specified number of input pulses between 0 and 2 147 483 647 Limits the number of retriggers allowed between resets between 0 and 2 147 483 647 To allow a channel to be triggered again after reaching the limit the channel must be reset To reset both channels press the Reset button on the LC220 or choose Actions gt Reset in Trig220 To reset only one channel click the Reset button next to the channel settings Sets the channel to be edge triggered In other words an input signal that stays high triggers the channel only
6. as those for Delayed Pulse After Triggering mode Normal Skip N triggers Retrigger N times Trigger on rising input Trigger on input high The channel can retrigger an unlimited number of times The channel triggers only after the specified number of input pulses between 0 and 2 147 483 647 Limits the number of retriggers allowed between resets between 0 and 2 147 483 647 To allow a channel to be triggered again after reaching the limit press the Reset button on the LC220 or choose Actions gt Reset Channels in Trigger Sets the channel to be edge triggered In other words an input signal that stays high triggers the channel only once This option is not used in this mode The panel LED for a dynamically delayed trigger will remain green until a valid input signal is detected When an input signal is detected the LED will glow red until the output signal is sent At this point the LED will return to green if retriggering is allowed or it will glow red to indicate that no more input signals will be accepted To try the dynamically delayed pulse mode You can simulate the experiment above using the trigger button to represent Sensor 1 and a delayed trigger in Channel B to represent the signal from Sensor 2 Connect your oscilloscope to the Output C to view the results 1 Under Time base settings choose internal clock X 1 8 320 ns time base 2 On Channel A s Properties window select Delayed Trigger
7. atible outputs Voltages in the range 2 5 5 V are TTL highs and voltages in the range 0 0 0 2 V are TTL lows Intermediate voltages should not be present on inputs and outputs except during transitions The inputs and outputs are protected against connection to 115 VAC When disconnected the inputs are read as TIL highs The LC220 can be connected to disconnected from the PC at any time without damage to either unit This ability allows you to program to LC220 at your computer then to take the unit to the experiment area for stand alone use Basic functions The LC220 provides two functional channels or internal signal paths At any time each channel can be assigned one of eight timing modes Timing modes include clocks counters delayed triggers etc You can set various properties for each timing mode for example the delay length on a Delayed Trigger All modes are aligned to a time base derived from an internal or external clock allowing resolution down to 5 ns Each channel also includes logic settings which specify the conditions that will trigger the channel A channel can be triggered by logical combinations of signals from the inputs and or the output of the other channel All settings and setting profiles for a particular experiment can be stored as an experiment file on your computer Experiment files bear a tr2 extension How you will use the LC220 In most cases you ll use the LC220 as follo
8. d Acrobat are regis tered trademarks of Adobe Systems Inc Trig220 software 2004 2005 LabSmith This manual 2004 2005 LabSmith No part of this document may be reproduced or distributed without the consent of LabSmith 47
9. d and appear in the Main Screen program summary area It is good practice to document your settings extensively As with all programming good documentation will simplify the process of creating debugging and running your experiments For each timing mode you ll be able to set up a simple example to view the output of the channel To set up for the experiments later in this section 1 Make sure that the LC220 is connected to the PC 19 2 Plug a normally open push button trigger switch into In1 The button will represent our triggering event 3 Open Channel A s Setting screen and select the Statically delayed pulse timing mode you ll learn about Statically delayed pulse mode shortly 4 Select the Logic tab and select the logical assignment hA Not hl Then click Apply With this logic Channel A will trigger when you depress the trigger button 5 Plug an oscilloscope to Output A to observe the channel output Remember the output voltage will vary from 0 to 5 V Apply versus Program All Channels Each properties screen includes an Apply button which when clicked will send the current timing properties to the channel on the LC220 The other channel function for example retriggering counters and triggering is not affected Program All Channels updates the time base settings and all the channel settings of the LC220 Both channels are reset 20 Fixed output mode Chann
10. delay is lt 20 ns ChannelA m Timing mode Toggled output v Trigger logic Toggle a Notes Force Trigger Toggle output at each trigger Enable Initial state Low Disable C High Reset Apply The only user settings for this mode are the initial state which may be either low or high The panel LED for the channel will glow green when the output is low or red when the output is high 40 RUNNING EXPERIMENTS Once you ve created a program you re ready to set up and perform your experiment Storing and recalling experiment files As mentioned earlier an experiment file is a document which resides on your PC containing all of the logic properties and settings profiles for a particular experiment Experiment files bear the tr2 extension To save an experiment choose Save As from the File menu Name the file then store it on your hard drive in an accessible place To reuse an experiment file choose File gt Open and locate the file When you click OK the file s settings will appear in Trig220 Click Program all settings to download the settings to the LC220 NOTE Good file naming protocol will help your experiments go more smoothly For example if you are saving multiple versions of a combustion experiment store all files in the same directory with the names combustion 1 trg combustion2 tr2 etc Or better yet use descriptiv
11. e names such as combust 50us delay tr2 combust 6Ous delay tr2 etc Panel controls and indicators The front panel of the LC220 is designed to help you run experiments without computer control This functionality allows you to program the unit at a workstation then to move the unit to the experimental environment Channel LEDs As mentioned earlier the LEDs for each channel provide information on each channel s status 1 A green light on a channel typically indicates that the channel is waiting for an input trigger When a channel is in Fixed output Clocked pulse stream Output Input or Toggled output timing modes the green light indicates that the output is currently LOW for that channel 41 2 Ared light typically indicates that the channel is in the process of triggering When a channel is in Fixed output Clocked pulse stream Output Input or Toggled output timing modes the red light indicates that the output is currently HIGH for that channel 3 When a channel indicator is steadily off the channel is disabled see Enable Disable Channels below The channel indicator also turns off during delays and while waiting for the input to return low for an edge trigger The following chart provides an overview of the front panel channel LEDs Mode Off Green Red Fixed output Output is Low Output is High Output Input Output is Low Output is High Passive Clocked pulse Out
12. e the output The quiescent state of a channel is the setting of its output when the channel is disabled You can set each channel s quiescent state to be a TTL high 3 5 5 V or low 0 0 2 V to provide a safe signal to the output device if you need to abort an experiment or stops its progress The method for setting the quiescent state depends on the timing mode Most modes include an Invert Output option which sets the output normally High 15 Logic A channel can be triggered by logical combinations of signals from the inputs and or other channel output Channel logic determines the combination of signals that triggers the channel To define when a channel will trigger open the channel s Settings screen then click the Logic tab This tab only appears for timing modes which respond to logic You will select a trigger logic assignment for the channel from a list of options Channel A Timing mode Statically delayed pulse v Trigger logic Delay Triggering Sweep Enable Operator Disable Reset Force Trigger Ind Apply we NOTE Some timing modes do not respond to trigger logic For example a channel set to operate as a clock will continue to run regardless of its input 16 Logic assignments The logic processor assigns the logical combination of external inputs In and In2 and other channel output that will trigger each channel Logic assignments have the followi
13. el A Timing mode Fixed output v Fired Enable Disable Reset m Fix output Apply In this mode the channel output remains in the selected state Low or High regardless of the input The panel LED for the channel will glow green when the output is low or red when the output is high To try fixed output mode On the Properties tab of Channel A choose Fixed Output Choose Low or High as the output state then click Apply to save the settings At Output A the signal will remain a steady TTL logic low or high depending on your selection 21 Passive mode Output Input Channel A Timing mode Output input Z Trigger logic Passive Enable Function C Dutput lInput invert Disable Reset Notes Apply In passive mode the output signal equals the input signal or its logical inverse sekk The panel LED for the channel will glow green when the output is Low or red when the output is high To try passive mode On Channel A s Settings screen select the Output Input timing mode In the Function box choose Output Input then Click Apply to save the settings When the trigger button is not depressed i e the input signal is low the signal at Output A will be a TTL low Now depress the trigger button at Input 1 the signal at Output A will go high If you select Output Input invert the chan
14. he Main screen 1 Menu options The File menu lets you open close and save experiment files tr2 files The Edit Menu lets you cut copy and paste text as you edit your program The View menu lets you set up the Trig220 interface Choose to display or hide the tool bars and status bar select the font used in Trigger and set up communications with the LC220 The Actions menu lets you modify the LC220 settings The buttons are as follows jose ose The Reset button resets both channels of the LC220 Retriggering counters and delay settings are reset as well The Program all settings button Se updates the LC220 with all current settings The Online Offline button ca toggles between Online and Offline mode In Online mode this button is depressed the Com port is open and settings are transferred to the LC220 In Offline mode this button is not depressed the Com port is available for other programs and settings are not transferred to the LC220 Offline mode is convenient for developing tr2 settings without an LC220 attached The Main window panel shows and controls all of the channel settings This summary may be printed for review and documentation purposes The text is not freely editable and must be modified through the dialogs Double clicking on selected parts of the summary opens the dialog needed to edit the text 11 Time base settings The Time base settings dialog lets you control the time base used by
15. ht functions that each channel can perform This mode toggles its output state upon every input pulse An input signal that initiates a channel function The control software for the LC220 Also known as Noise Suppression mode This timing mode eliminates false triggers due to noise on the input signal by requiring the signal to remain high or low for a specified duration This menu function allows you to upgrade your LC220 s firmware to the latest version available at www labsmith com To Our Valued Customers User s Manual and Trig 220 Control Software To obtain the most up to date version of this user s manual and Trig220 Control Software please refer to our website at http www labsmith com Corrections to this user s manual and Trig220 Control Software Please contact support labsmith com to report any information that is missing or in error in this user s manual or in the Trig220 Control Software Sample Files and Application Notes Sample files application notes and other technical information are available on our website To request sample files specific to your application please contact support labsmith com Trig220 and LC220 are trademarks of LabSmith National Instruments is a registered trademark of National Instruments Inc LabView is a trademark of National Instruments Inc Microsoft Windows 95 98 Me NT 2000 and XP are registered trademarks of Microsoft Corporation Abobe an
16. l ALED on the front of the LC220 glows green while the channel output is LOW or red when the output is HIGH But don t be confused The channel LED does not always indicate the channel s output state only in certain Timing modes You ll learn more later in the Timing modes section Next change the logic assignment to InA Not Inl Click the Program All Settings button Se The LED at Output A will now remain off until you close the switch Change the logic assignment to InA Not In2 10 Click the Program All Settings button The LED at Output A will now remain off until you close Switch 2 11 Lastly change the logic assignment to InA Not In1 And Not In2 12 Click the Program All Channels button The LED at Output A will remain off until both switches are closed Timing modes In the previous section you learned that logic defines how channels are triggered In this section you ll use the LC220 timing modes to determine how the channels will respond Each channel can be configured to operate in one of eight modes Fixed output Output Input Passive mode Statically delayed pulse Clocked pulse stream Validated trigger input Noise suppression mode Dynamically delayed pulse Timer Toggled output When a timing mode is selected the relevant property tabs will be displayed l ll NOTE All timing property tabs include a space for Notes These notes are save
17. lse will increase with each trigger Important delay timing considerations Once the LC220 has begun a delay sequence it ignores incoming trigger pulses There is also a delay of approximately 10 us at a 5 ns time base after the completion of a delay sequence while 29 the channel resets for the next trigger This effect can be used to skip triggers but if misunderstood it can cause unexpected results For example in the diagram below two trigger pulses arrive 100 us apart The channel is functioning in Statically delayed pulse mode with a delay of 50 us and a duration of 45 us pulse It would receive the first pulse wait 50 us send a 45 us output pulse and trigger again at the second pulse But the extra 10 us delay at the end of the sequence will cause the channel to ignore the second trigger pulse i t 0 ps first trigger pulse 1 t 100 us second trigger pulse I 1 I 1 l 1 I i i 1 1 I 1 l ie A 1 rot i i t 50 us t 95 us delay t 105 us channel ready output sequence ends for next trigger pulse pulse sent 30 Validated trigger input mode noise suppression Channel A m Timing mode Validated trigger input hd Trigger logic Validate Triggering m Minimum duration of valid trigger delay Duration of pulse O 30 Jus C Until reset Enable Disable Reset Inverted output pulse from high to low m Notes Apply Force T
18. ming controller for coordinating and synchronizing lab equipment and physical experiments The LC220 provides clocks counters triggers and many other useful functions with up to 5 ns resolution and 100 ps accuracy As you are well aware controlling and synchronizing experimental equipment are often the most tedious tasks you ll face in the lab Experimenters regularly build their own controls from scratch or piece together systems from the limited offerings on the market The LC220 simplifies your control setup so you can go about the business of gathering data and making knowledge The LC220 consists of two components Trig220 software and the LC220 logic and timing controller Trig220 lets you configure and run experiments from a simple graphical interface The LC220 controller provides the connections and control for your experimental devices Parts list Your LC220 package should include the following items 1 the LC220 controller 2 AC wall transformer 3 Trig220 software installation CD 4 9 pin RS232 cable 5 User s manual If any parts are missing or damaged please contact LabSmith support Specifications Trig220 software will run on any PC compatible computer running Microsoft Windows 95 98 Me NT 2000 or XP Drivers for National Instruments LabView software are also available for download See http www labsmith com for more information The LC220 includes two TTL compatible inputs and two TTL comp
19. n the Delay tab enter a delay of s and duration of 500 ms On the Triggering tab choose Retrigger N Times and set N 0 Choose Input high level trigger then click Apply to save the settings Click the trigger pushbutton One second after you push it the output of Channel A will go high for 500 ms The channel LED remains red indicating it is not ready to trigger Push the button again You ll see that you cannot retrigger the channel Click the Reset button on the LC220 the LED glows green and you can once again trigger the channel On the Triggering tab choose Retrigger N times set N 5 then click Apply Depress and hold the trigger button As long as the trigger is depressed i e the input signal is high the channel will continue to trigger until the limit is reached Again on the Triggering tab select Rising Input Edge Trigger then click Apply Depress and hold the trigger button The channel will trigger only once no matter how long you hold the button Release the button and depress it again and the channel will be triggered once more switch bounce may produce triggers when the button is released On the Delay tab check Inverted output then click Apply The output will be the inverse of that described in Step 4 On the Sweep tab set the sweep to 0 5 s per trigger and on the Delay tab select Normal Click Apply The time delay before the output pu
20. nel output will remain high until you depress the trigger 22 Clocked pulse stream mode Channel A Timing mode Clocked pulse stream Clock m Clock high duration Pei s u amp Clock low duration 20 us v Inverted output Disable Reset Notes kkl Apply In clock mode the output of the channel is a steady stream of pulses You set the pulse duration and delay between pulses A clock channel s input does not affect its output The panel LED for a clock channel will glow green when the output is low or red when the output is high pee NOTE For a high frequency clock the LED will alternate between red and green so quickly that it will appear as a continuous pale green yellow or orange light 23 As mentioned earlier the LC220 can operate with different time bases see Time Base Settings With a 5 ns time base internal clock X 8 the clock pulse and duration can range from 0 48 us to 52 4 ms At longer time bases this range is proportionally longer for example at 320 ns time base internal clock X 1 8 the pulse duration can range from 30 1 us to 3 35 s To set the pulse duration select the timing units seconds microseconds milliseconds or nanoseconds then enter a duration in the Clock high duration box x To set the time between pulses select the units then enter the duration in the Clock low duration box A clock s quiescen
21. ng format the channel to be triggered the conditions that will trigger it Here is an example InB In2 This assignment means Channel B will be triggered when the signal on In2 goes TRUE reaches 5 V The assignment InB Not In2 means Channel B will trigger when the signal on In2 goes FALSE drops below 0 2 V You can employ compound arguments in logical assignments such as InB Not OutA And In2 This means Channel B will trigger when the output of Channel A is FALSE and In2 is TRUE er NOTE LC220 inputs are TRUE by default if nothing is connected i e the input is normally weakly pulled high Grounding an input switches its state to a logical FALSE 17 Experimenting With Channel Logic This brief example will show you more about channel logic 1 2 3 6 Connect a normally open switch to In1 and another to In2 Connect an LED to OutA Choose Output Input from the Timing mode list for Channel A In this mode the output of Channel A is always the same as its input Select the Passive tab and choose Output Input Select the Logic tab and select inA inl Click the Program all settings button The LED at OutA should be glowing indicating that the output is TRUE or HIGH since LC220 inputs are normally HIGH When you close Switch 1 the LED will turn off indicating that the output is FALSE or LOW 18 NOTE The Channe
22. once Allows the channel to be repeatedly triggered while an input is high This setting could be used for generating a low precision gated clock for example However the latency time between retriggers is indeterminate typically around 10 us so a clock made this way is not suitable for applications requiring high precision 27 Sweep Channel A Timing mode Statically delayed pulse v Enable M Sweep delay Delay increment per trigger Disable Reset Force Trigger eid Apply To facilitate time delay scanning experiments the delay of the pulse relative to the trigger can be swept or incremented by a specified value each time the channel is triggered The sweep value must be positive The increment resolution is equal to the time base e g as short as 5 ns The panel LED for the delayed trigger will glow green until an input signal is detected The LED will be unlit for the delay time and will glow red for the duration time What happens next depends upon the channel settings 28 Retriggering Edge The channel LED enabled triggered no yes or no remains red no more triggers accepted no glows green waiting for next trigger yes is off glows green once input goes low To try the delayed pulse mode 1 2 3 10 Under Time base settings choose internal clock X 1 8 320 ns time base In Channel A s properties screen select Statically delayed pulse O
23. or another input pulse 33 Timer mode Channel A Timing mode Timer Trigger logic Counter m Last delay between input pulses Saas fo us v ave measurements to file Reset l Hold measurement Disable fia C Force Trigger Apply The counter timer mode determines the time delay between two separate input signals and reports it back to the PC You can view the counter output in the Properties tab Use the channel s logic to select the input signals that will be compared by the timer see Channel Properties Logic above Normally the counter will report a value each time a pair of pulses is measured To retain the current measurement check the Hold measurement button the counter will not update the delay display until this button is cleared 34 wel NOTE To switch from Timer mode first click the Disable button and ensure the channel LED is unlit indicating that the channel is disabled This will help you avoid unexpected behaviors when the counter is transmitting measurements rapidly e g gt LOOO measurements per second NOTE When you first run the LC220 channels that are configured as counters are initially disabled and must be enabled either by clicking the Enable button on the channel s Properties screen or by using the front panel See Experimenting Disable Enable Channels below The panel LED for the timer will be green un
24. ort Baud rate Com8 38400 v Cancel 6 Select the port to which the LC220 is connected The LC220 will automatically detect the baud rate which is typically set to 38400 If the RS232 cable running to your LC220 is greater than 30 m long you may need to lower the baud rate to achieve reliable communication Field upgradeable software The firmware in the LC220 is field upgradeable allowing access to new timing modes and capabilities as they become available To upgrade the firmware download the latest version from www labsmith com Then choose Update Firmware on the Actions menu to load data from that file Getting help This guide is your main source for information on operating the LC220 and Trig220 software The guide is also available in an Abobe Acrobat Portable Document Format pdf file for electronic viewing Check the LabSmith web site www labsmith com for helpful applications notes and other technical information to help you use the LC220 If you are unable to find the information you need please contact our technical support team at 925 292 5161 or e mail us at info labsmith com If you need to contact support please let us know your LC220 serial number located on the bottom of the unit and the version of software you are using To determine the software version number select About Trig220 from the Help menu About trig220 trig220 Version 1 0 Uma Co
25. out actually performing the live experiment You can also trigger a channel from within the Trig220 software See Channel Properties Force Trigger above Reset The Reset button returns both channels to the last programmed settings It resets and reinitializes retriggering counters and the delays of any channels that are undergoing a delay sweep 43 GLOSSARY Apply Baud Rate Channel Channel input Channel settings Com port Controller Counter timer mode Delay Duration Dynamically delayed pulse Edge triggering Enable disable outputs External clock Firmware 44 Sends a channel s current timing settings to the LC220 The speed of communication via the Com port One of eight internal signal paths in the LC220 The signal which feeds one of the eight channels A channel input can be triggered by signals from any combination of signals from the input jacks and or channel outputs The logic and timing settings which determine how a channel functions A serial port on a PC computer The LC220 communicates with the computer via an RS 232 cable connected to a Com port The LC220 hardware unit This timing mode determines the time delay between two separate input signals The time between the arrival of an input trigger and the release of an output pulse The length of an output pulse This timing mode measures the time difference between two pulses scales that difference by a user defined factor wait
26. put is Low Output is High stream Statically delayed In delay period Waiting for trigger if In duration period if pulse retriggering is on retriggering is off light will glow green light remains red after once input goes low duration period Validated trigger Waiting for trigger if In duration period if Noise suppression retriggering is on light will glow green once input goes low retriggering is off light remains red after duration period Timer Timer data is being Waiting for first Waiting for second reported waiting for trigger pulse trigger pulse input to go low Dynamically delayed Waiting for trigger if In duration period if pulse retriggering is on retriggering is off light will glow green light remains red after once input goes low duration period Toggled output Output is Low Output is High 42 pe NOTE Channel LEDs provide important information about the channels but an oscilloscope remains a useful tool for diagnosing channel outputs particularly for high speed experiments Output LED The output right most LED glows green when outputs are enabled and red when outputs are disabled See Running Experiments Disable Enable channels below Trigger A and Trigger B This function lets you simulate an input trigger on the respective channel regardless of the channel s logic settings or state This is a useful way to initiate a timing sequence with
27. pyright C 2004 2005 LabSmith All rights reserved http www labsmith com OVERVIEW OF LC220 CONTROLS The LC220 is the control unit and interface for your experimental equipment You will program it using the Trig220 software Once you ve designed tested and downloaded your program you can control the LC220 from the computer or you can run it in stand alone mode Indicators and controls on the LC220 will help you run your experiments You ll learn all about these functions in the Experimenting section later For now we ll give you a short tour of the inputs outputs and controls so you can work with the unit while you learn to use the Trig220 software i LabSmith LC220 Logic Controller gt _TL Y OutB JL Inputs Indicators Channel A Trigger Trigger Reset A B Power PC link Inputs and outputs The LC220 includes the following connectors a 2 1 mm power jack center positive for 6 to 9 V DC 0 6 A power source a 9 pin RS232 jack to connect to the Com port of your PC two channel input BNC jacks inl and in2 normally high 5 V two channel output BNC jacks outA and outB normally low 0 V inl doubles as an input jack for an optional external clock source The input and output voltages conform to the TTL standards Panel controls There are three buttons on the LC220 Trigger A and trigger B respectively force channels A and B to be triggered The effect this
28. rigger eid The noise suppression function eliminates false triggers due to noise on the input signal by requiring the signal to remain high or low for a specified duration If the signal drops out during that period the output will remain low and the channel will look for the next input signal Once an input signal is deemed valid a pulse of user specified duration will be sent to the channel output Unlike an analog filter which smears the signal edge this noise suppression function digitally blocks false triggers retaining the sharp edges on the real trigger signal As with Statically delayed pulse mode you have additional controls over the channel On the Validate tab choose 31 Minimum duration The minimum length of an input pulse that will trigger the channel Duration of pulse The duration of the output signal Until Reset The output will remain high after a valid trigger until the channel is reset Inverted Output Check the box to set the output high until a valid trigger On the Triggering tab choose Normal The channel can retrigger an unlimited number of times Skip N triggers The channel triggers only after the specified number of valid input pulses between 0 and 2 147 483 647 Retrigger N times Limits the number of retriggers allowed between resets between 0 and 2 147 483 647 To allow a channel to be triggered again after reaching the limit the channel must be reset To reset both channels pres
29. s the Reset button on the LC220 or choose Actions gt Reset in Trig220 To reset only one channel click the Reset button next to the channel settings Trigger on input high While the input is high channel can be repeatedly triggered Trigger on rising input Sets the channel to be edge triggered i e an input signal that stays high will only trigger the channel once The panel LED for the noise suppression channel will glow green until an input signal is detected It will then glow red until the duration period has elapsed At this point the LED will respond as follows Retriggering Edge LED enabled trigger no yes or no remains red no more triggers accepted no glows green waiting for next trigger is off glows green when trigger goes low 32 To try validated trigger mode 1 2 3 Under Time base settings choose internal clock X 1 8 320 ns time base In Channel A s properties select Validated Trigger Input mode On the Validate tab enter a Minimum duration and Duration of output pulse of 1 second each On the Triggering tab select Retrigger N times and set N 50 Click Apply to save the settings Now depress the trigger button If you hold the button down for more than one second the minimum duration the output of Channel A will go high If you release the button before one second elapses the output will remain low and the channel will wait f
30. s the duration of that calculated delay then sends a pulse to the channel output This channel setting ensures that an input signal which stays high will only trigger the channel once A function which disables or suspends a channel or all channels temporarily A signal applied to in1 that can optionally be used to generate the time base of the LC220 The internal code of the LC220 controller The firmware as well as the Trig220 control software can be field upgraded Latest upgrades are available at www labsmith com Input Lock unlock panel Logic Noise suppression Output Program all settings Programmable logic controller Reset Retrigger Scaling Settings file Skip triggers Statically delayed pulse Sweep One of two input jacks on the LC220 Signals from these inputs can be logically combined to trigger either channel A function that disables all front panel functions including the power button to avoid tampering accidental changes when the LC220 is embedded in an experiment The set of assignments that determines when a channel will trigger Also called Validated Trigger Input mode This timing mode eliminates false triggers due to noise on the input signal by requiring the signal to remain high or low for a specified duration One of two output jacks on the LC220 The output signals are determined by the timing channels A function which sends all logic and timing settings
31. t state is normally low See Channel Properties Quiescent States Check the Inverted output box if the quiescent state for the channel should be high instead To try Clock mode 1 On the Time base settings screen select internal clock and a clock multiplier of 1 8 X 2 On Channel A s Properties tab choose Clock as the mode select an on duration of 100 ms and an off duration of 500 ms Click Apply to save the settings The signal at Output A will go repeatedly go high for 100 ms then go low for 500 ms 24 Statically delayed pulse mode Upon receiving an input signal a delayed trigger waits a specified delay time then sends a pulse to the channel output This mode has several property tabs Delay Channel m Timing mode Statically delayed pulse w Trigger logic Delay Triggering Sweep m Delay after trigger Enable Duration of pulse Disable Until reset Reset Inverted output pulse from high to low Notes l Force Trigger klk Apply On the Delay tab you ll specify Delay after trigger The delay between a valid trigger and an output signal Duration of pulse The duration of the output signal Until Reset The output will remain high after a valid trigger until the channel is reset Inverted Output Check the box to set the output high until a valid trigger 25 The range of settings you can use with the delayed trigger depend
32. the LC220 for timing The LC220 measures delays and pulses in increments of this time base For higher timing resolution you can use a higher clock multiplier For longer delays select a lower clock multiplier A variety of multipliers are available to optimize the increment for your needs To reach this screen click Set time base options from the Action menu Time base settings Clock source nternal 25 MHz oscillator C Int Clock multiplier 4x Time base fio ns Cancel Clock source The LC220 can derive its time base from an internal 25 MHz oscillator or from a TTL pulse train provided to In1 If the time base is derived from the external input you must specify the frequency of this time base so that Trig220 can set the LC220 timing correctly If the clock frequency specified is 10 higher than actual the channels using this time base will be 10 long on delays and duration Clock multiplier The clock source is multiplied by a user specified factor to form a high frequency source for the time base For example a multiplier of 4 X on the 25 MHz internal oscillator produces a clock of 100 MHz for a time base of 10 ns 12 Time base The calculated time base is indicated in this window This must not be less than 5 ns or greater than 1000 ns for proper operation General options The General options dialog lets you enable and disable the channel outputs and lock or
33. til the first trigger red until the second trigger and off while the count data is reported and the channel waits for the input to return low The output of a channel in timer mode is always high NOTE The LC220 may be measuring time differences faster than it can display them all on the monitor Now check Hold measurement Note that the displayed measurement does not change Un check Hold Measurement then check Hold measurement again to freeze another measurement Dynamically delayed pulse mode The dynamic delay is a unique feature First it measures the time difference between two pulses like a counter Next it scales that difference by a user defined factor It subtracts an offset value waits the duration of the dynamically calculated delay then sends a pulse to the channel output 35 a NOTE The dynamic delay is particularly useful for ballistics or gas dynamics experiments in which the velocity of a projectile or wave must be calculated and used to time the triggering of an experimental device Dynamically delayed pulse mode includes several properties tabs Scaling Channel Timing mode Dynamically delayed pulse v Trigger logic Scaling Delay Triggering Scale measured up count by Enable Disable Reset Force Trigger ei Apply 36 In the calculation of the delay the measured delay between two pulses is scaled by a fac
34. to the LC220 A device which combines logic and timing processors for precise control of physical experiments Returns all channels of the LC220 to their waiting condition Retriggering Counters and delay settings are reset as well A channel setting that allows the channel to be triggered more than once if subsequent trigger pulses are received In the Dynamically Delayed Trigger timing mode scaling determines the ratio of the distance between the two input sensors to the distance of the target A PC file with a tr2 extension that contains all the logic and timing settings for an experiment A setting that allows a channel to trigger only after the specified number of input pulses In this timing mode a channel waits for an input signal waits a specified delay time then sends a pulse to the channel output In the Delayed Pulse After Trigger timing mode this settings facilitates time delay scanning experiments in which the delay of the pulse relative to the trigger must be incremented by a specified value each time the channel is triggered 45 Time base Timer Timing mode Toggle mode Trigger Trig220 Trigger validation mode Update firmware 46 The minimum increment of time used by the LC220 This can range from 5 ns to 1000 ns and can be generated from an internal or external clock Counter Timer mode determines the time delay between two separate input signals and reports it back to the PC The eig
35. tor of 2 where 16 lt N lt 16 or N 16 where 0 lt N lt 256 The former scaling is faster and a scaling of 1 1 is fastest Scaling can typically be done at rates gt 50 kHz at a 5 ns time base The maximum delay between input pulses is 52 ms at a time base of 5 ns and 3 3 s at a time base of 320 ns The maximum delay resulting from the scaling and offset calculations is respectively 21 47 s and 1374 s at 5 ns and 320 ns time bases Delay Channel A m Timing mode Dynamically delayed pulse v Trigger logic Scaling Delay Triggering Added delay can be negative Enable 20 Jus ba m Duration of pulse Disable g 20 Jus c Until reset Reset Inverted output pulse from high to low Notes Force Trigger Apply Added Delay Set an offset value to subtract from the scaled delay length This is useful when accounting for camera shutters or other lag times in experimental equipment The offset value can be positive shortens the 37 Duration of pulse Until Reset Inverted Output Triggering delay time or negative lengthens the delay time and the resolution is set by the time base e g 10 ns The duration of the output signal The output will remain high after a trigger until the channel is reset Check to set the output high until a valid trigger The duration of the pulse and other properties are the same as for the delayed trigger The triggering options are the same
36. unlock the panel buttons To open this dialog click Set LC220 options under the Actions menu General options Status OK Lock Panel Disable Dutputs Unlock Panel Close Disable enable outputs Disabling outputs prevents the LC220 from sending trigger pulses to its output connectors regardless of the inputs or the actions of the channels Enabling the outputs allows the LC220 to send trigger pulses to its output connectors These functions are nonvolatile the enabled and disabled states are restored on power cycle Lock unlock panel Lock or unlock the front panel buttons using the Lock Panel and Unlock Panel buttons This functionality is handy for example in an embedded control application where the LC220 should function only in stand alone or computer controlled modes When the panel is locked the buttons are not illuminated When the panel is unlocked the front panel buttons are illuminated Like the enable disable I O functions these settings are nonvolatile and are restored on power up 13 CHANNEL PROPERTIES Channel properties screen Both channels have a Settings screen in the main application window in which you ll select the timing mode set the timing properties and establish the logic that will determine when the channel will trigger Channel A Timing mode Statically delayed pulse v A Delay Triggering Sweep Enable Disable Reset
37. ws 1 Using the Trig220 software open an existing experiment file or create a new file 2 In Trig220 or LabView program the properties and logic for each channel and for the experiment as a whole 3 Send the properties and logic to the LC220 s memory 4 Test your program by simulating triggers and examining the outputs using the LC220 s channel LEDs and or an oscilloscope or other diagnostic tool 5 Plug your experimental equipment to the LC220 6 Run the experiment using the LC220 by itself or leaving it tethered to the PC Installing Trig220 Software Insert the Trig220 Software disk in your CD ROM drive and execute the setup exe file Setting up the LC220 1 Verify that your wall socket provides AC voltages within the range setting on the wall transformer supplied with the LC220 If the voltage range is not correct contact LabSmith support labsmith com for an alternate DO NOT connect the wall transformer to a socket that is beyond the transformer s range setting Plug the transformer into an appropriate socket and connect the power to the LC220 Connect the 9 pin cable to the back of the LC220 and to a free serial port on the PC Press the Power button on the front of the LC220 From your computer run Trig220 exe to launch the Trig220 software From within Trig220 select View gt Communications options The Communications properties screen will open Communications properties Serial p
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