LC880 user`s manual v5
Contents
1. Enable Disable Ronee Migger OK Apply Cancel In this mode the channel output remains in the selected state Low or High regardless of the input The front 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 15 On the Properties tab of Channel A choose Fixed Output from the pop up 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 Passive Mode Output Input Timing mode Clocked pulse stream Clock high duration Enable fio us z Clock low duration Disable E Us i Reset Inverted output Motes Ronee Wigg er In passive mode the output signal equals the input signal or its logical inverse The front 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 1 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 channel output will remain hi2. Scaling Channel C Ed Timing mode E pnamically delayed pulse Scale measured up count by Enable f 2 1B lt N lt 16 fast sjo NAB 0 lt N lt 256 slower N 16 Disable OF Apply Cancel In the calculation of the delay the measured delay between two pulses is scaled by a factor 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 The maximum delay between input pulses is 52 ms in hi res mode 100 MHz and 3 3 s in low res mode 100 64 The maximum delay resulting from the scaling and offset calculations is respectively 21 47 s and 1374 s in hi res and low res modes Negative calculated delays work correctly only in acausal universes 25 Delay Added Delay Duration of pulse Until Reset Inverted Output Triggering Channel D X Timing mode E pnamically delayed pulse Added delay can be negate g us f Duration of pulse io fio Us C Until reset Enable Disable Inverted output pulse from high to low Notes Ronee Wrigger OF Apply Cancel 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 delay time or negative lengthens the de
3. OK Global Vanables Logical statements that are used repeatedly in your experiment can be stored as global variables With global variables complex logic is easier to read and debug Say that several channels in your experiment need to be triggered by the same event For example Channels F G and H must trigger when inl or in2 and outC or outD Rather than typing that logic each time you may define it as a variable event inl or in2 and outC or outD Now you can use event in the logic for Channels F G and H inF event To view the global variables click the Globals button on the Logic tab The Globals screen will open Global Symbols Ed Logic Symbols ffthese definitions apply for all channels atm Inz fire in and arm ox ae en To create a new global variable type the variable s name followed by its definition In this example we ve defined variables named arm and fire Be sure to end your definition with a semicolon Click Apply to save the variable Parsing When you have completed a logical statement click Apply or OK Trigger will check the statement for syntactical and logical errors and will report any mistakes to you by line number Sending Logic When you alter channel logic you must transfer the changes to the LC880 to implement it 31 To transfer logic to the LC880 click the Set All Channels b
4. 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 pulse will increase with each trigger Validated Tigger Input Mode Noise Suppression Channel B X Timing mode Validated trigger Input J Minimum duration of walid trigger delay g us f Duration of pulse io g TE C Until reset Enable Disable Inverted output pulse from high to low Notes Trigger 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 21 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 Delayed Pulse After Trigger mode you have additional controls over the channel On the Validate tab choose Minimum duration The minimum length of an input pulse that will trigger the channel Duration of pulse The duration of the output s
5. We Labsmith TOOLS FOR SCIENCE LC880 Experiment Controller User Guide Documentation for the LC880 Controller and Trigger Control Software v 5 0 Trigger software 1996 2002 LabSmith This manual 2002 LabSmith No part of this document may be reproduced or distributed without the consent of LabSmith INTRODUCTION 5 Parts List 5 Specifications 5 Basic Functions 5 How You ll Use the LC880 6 Installing Trigger S oftware 6 Setting Up the LC880 6 Getting Help 7 OVERVIEW OF LC880 CONTROLS 8 Back Panel Inputs and Outputs Front Panel Controls 9 TRIGGER SOFTWARE INTERFACE 10 Main Screen 10 General Settings 11 Disable Enable I O 11 Lock Unlock Panel 11 Time base settings 12 CHANNEL PROPERTIES 13 Channel Properties Screen 13 Quiescent States 14 Timing Modes 14 Apply versus Program All Channels 15 Fixed Output Mode 15 Passive Mode Output Input 16 Clocked Pulse Stream Mode 17 Delayed Pulse After ngger Mode 18 Validated Tngger Input Mode Noise Suppression 21 Counter Timer Mode 23 Dynamically Delayed Pulse Mode 25 Toggled Output Mode 28 Logic 28 Predefined Vanables 30 Global Vanables 31 Parsing 31 Sending Logic 31 RUNNING EXPERIMENTS Storing and Recalling Experiment F iles Front Panel Controls and Indicators Channel LEDs ALL Channel LED Selecting a Channel from the Front Panel Performing a Front Panel Function Enable Disable ALL Enable Disable Channel Tiggera Channel Reset S
6. between 1 and 100 MHz applied to the external clock input on the back of the LC880 This allows multiple LC880s to be synchronized to the same time base high precision external time bases to be used or variable frequency time bases to be used This time base cannot be produced by a channel using the time base as an input Ext 64 time base mode divides the frequency of the signal applied to the external clock input before using it as a time base If the external clock is being used as a time base the frequency entered into the edit box is used to calculate the timing settings For example if this setting is 10 higher than actual the channels using this time base will be 10 long on delays and durations 12 CHANNEL PROPERTIES Channel Properties Screen Each channel has a Settings screen in which you ll select the timing mode set the timing properties and establish the logic that will determine when the channel will trigger To open the Settings screen for a channel select the channel from the Channel menu or click a channel button A H on the Main screen You can open more than one channel screen at a time Channel B X Timing mode Delayed pulse after trigger Delay Triggering Sweep Combinatorial logic for tigger input Enable nE not ine Disable Trigger Predefines Globals x C ce Channel properties are organized by tabs The tabs that are relevant
7. 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 The range of settings you can use with the delayed trigger depend upon the current timing mode 18 100 high res mode 100 64 low res mode Delay range 20 ns to 21 47 s 1 28 us to 1374 s 17 ysto2147s 493 ps t0 1374 resolution Triggering Channel B X Timing mode Delayed pulse after trigger Enable Normal f Skip H triggers N 25 Retrigger N times Disable Trigger on C Input high level trigger Rising input edge trigger m sler host computer tolovma mager Motes Trigger OK Apply Cancel This tab lets you control how the channel will trigger 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 LC880 or choose Program gt Reset Channels in Trigger Sets the channel to be edge triggered In other words an input signal that stays high triggers
8. 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 Timing Modes In this section we ll begin to use the various LC880 timing modes Each channel can be configured to operate in one of eight modes Fixed output Output Input Passive Mode Delayed Pulse After Trigger Clocked Pulse Stream Validated Trigger Input Noise Suppression Dynamically Delayed Pulse Counter Timer Toggled Output When a timing mode is selected the relevant property tabs will be displayed NOTE All timing property tabs include a space for Notes These notes are saved and appearin the Main Screen program summary area It isgood practice to document your settings extensively As with all programming good documentation will simplify the process of creating debugging and running your expenments 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 below 1 Make sure that the LC880 is connected to the PC 2 Plug a normally open push button trigger switch into Input 1 The button will represent our triggering event 3 Open Channel A s Sett
9. the channel only 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 19 Alert host computer Sends a ping to the PC upon completion of the trigger cycle following trigger Sweep Channel B X Timing mode Delayed pulse after trigger Enable M Sweep delay Delay increment per trigger e 025 Ls i Disable Trigger OK Apply Cancel 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 5 ns However the actual delay is rounded to the nearest 10 ns at full internal clock For example if the increment is set to 5 ns the actual delay is incremented by 10 ns every second trigger event The front 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 Retriggering Edge the channel LED enabled triggered no yes or no remains red no more triggers accepted yes no glows gree
10. version number select About Trigger from the Help menu About trigger X trigger Version 5 0 ge Copyright 1996 4002 LabS mith Http ien labsroth cor email labsmithtlabsmith com OVERVIEW OF LC880 CONTROLS The LC880 is the control unit and interface for your experimental equipment You will program it using the Trigger software Once you ve designed tested and downloaded your program you can control the LC880 from the computer or you can run it in stand alone mode Indicators and controls on the LC880 front panel 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 Trigger software Back Panel Inputs and Outputs Channel Inputs Clock Input 110 220 VAC m EP FA D h i Ya Wa d Yi i i gal BD DOE AE ar i _ The back panel includes the following connectors an internally fused jack for a standard 110 250 VAC power cord a 9 pin RS232 jack to connect to the Comm port of your PC eight BNC channel input jacks inl in8 normally high 5 Volts eight BNC channel output jacks outA outH normally low 0 Volts a BNC input jack for an external clock source The inputs and outputs will accept any device into that sends or receives TTL compatible signals Front Panel Controls Power Switch C
11. Channel Properties Quiescent States Check the Inverted output box if the quiescent state for the channel should be high instead NOTE in the nomal clock state a high input tums the clockon and a low input tums it off If the Inverted output box ischecked a low input tums the clock on and a high input tums tt off 17 To try Clock mode 1 On the General Settings screen select 100 64 low resolution mode for Channels A and B 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 high every 500 ms and will remain high for 100 ms each time To test faster clock settings select Full high resolution mode under General Settings then set duration and delay times of less than 52 ms Delayed Pulse After Tigger 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 B X Timing mode Delayed pulse after trigger Delay after trigger Enable 20 ust Duration of pulse Disable io fio Jus C Until reset Reset Inverted output pulse from high to low Notes Force Trigger ae til OK Apply Cancel On the Delay tab yov Il specify Delay after trigger The delay between a valid trigger
12. Storing Settings profiles lets you switch between settings while running an experiment to test different timing criteria initial conditions etc without re plugging or reprogramming Settings profiles are enumerated AA AB BA BB HH and they are accessible by pressing those buttons To store the current settings in a Settings profiles L Click the Store button 2 Click the two letter combination for the Settings profile Similarly to recall a stored Settings profile L Click the Recall button pA Click the two letter combination for the Settings profile You can recover these settings even after the unit has been turned off or disconnected The most recently used setting is automatically loaded when the LC880 is powered up If you attempt to recall an invalid setting the power LED flashes red and the system retains its previous setting To recall a setting profile from within Trigger 1 Click the Recall Setting from the Program menu 2 Click on or type in the desired setting case insensitive 3 Click Recall Select location of setting to recall Ed Locations ty o FY 3 yo an on en n n ee E n n E E e E M EEE M en en en E a Ee S en E e E a Eae S E en en E a Ee S E E ee E a Ee M en en e E an E E i Selected location joc cancel To store a setting profile from within Trigger 1 Click the Store Setting from the Program menu 2 Click on or type in the desi
13. a free serial port on your PC 3 Press the Power button on the front of the LC880 4 From your computer run Trigger exe to launch the Trigger software 5 From within Trigger select View gt Options gt Com Port The Serial Communications screen will open Serial communications properties Ea Serial port E Hone f COM C COM2 C COM3 C COM4 Cancel Baud rate 30400 6 Select the port to which the LC880 is connected The LC880 will automatically detect the baud rate which is typically set to 38400 If the RS232 cable running to your LC880 is greater than 30m long you may need to lower the baud rate to achieve reliable communication Getting Help This guide is your main source for information on operating the LC880 and Trigger software The guide is also available in an Adobe Acrobat Portable Document Format pdf file for electronic viewing While running Trigger press F1 to view this document on line Or press SHIFT F1 then select a button or menu option to view help topics for a particular feature The LabSmith web site www labsmith com also includes helpful applications notes and other technical information to help you use the LC880 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 the version of software you are using To determine the software
14. button glows a steady red and all buttons are dark When the panel is unlocked this LED glows green and front panel buttons are illuminated Like the enable disable IO functions these settings are nonvolatile and are restored on power up Because the power button is disabled the LC880 must be disconnected from AC power to turn it off if the front panel is locked 11 Time base settings General Settings Time base settings Time base Frequency MHz 100 100 64 Ext Ext 64 Channels 4 andB e E C Enable oO Channels C and O a N Disable lO Channels E and F C O C O Channels G and H F Unlock Panel Lock Panel Each pair of channels of the LC880 can independently utilize one of four different time bases so you can control and measure events that occur a few nanoseconds apart or a few hundred seconds apart In 100 MHz time base mode the default the LC880 aligns signals to an internal 100 MHz clock for timing resolution of 10 ns Use this hi res mode when the events of your experiment occur in rapid succession milliseconds or less 100 64 MHz time base mode allows the LC880 to control events that occur over longer time periods milliseconds to minutes This mode is called low res mode in the following documentation In Ext time base mode the channels use an external clock input for the time base This input must be TTL level
15. e button then clicking a channel button or the ALL channels button Enable Disable Channel It is sometimes convenient to disable or suspend a channel temporarily The Enable Disable channel functions provide this capability from the front panel The channel disable function is volatile channels will be re enabled on power up To disable a channel in a non volatile way set the timing mode to Fixed or disable the input by setting the logic to LOW etc You can also disable a channel or all channels from within Trigger see Trigger Software Interface General Settings Disable Enable Channels Tnggera Channel This function lets you simulate an input trigger on a channel regardless of the channel s logic settings This is a useful way to initiate a timing sequence without actually performing the live experiment You can also trigger a channel from within the Trigger software See Channel Properties Force Trigger above NOTE You cannot tigger ALL channels only individual channels Reset The Reset button returns the selected channel or ALL channels to the last programmed settings It resets and reinitializes retriggering counters and reinitializes the delay of any channels that are undergoing a delay sweep 35 Store Recall Settings Profiles As you know you can store 64 different Settings Profiles in the LC880 A Settings profile includes properties variables and logic for each of the eight channels
16. f these properties in settings profiles in the LC880 You can then switch between 5 settings profiles to switch experiments compare different timing scenarios or simulate different real world conditions All settings and settings profiles for a particular experiment can be stored as an experiment file on your computer Experiment files bear a trg extension How You ll Use the LC880 In most cases you ll use the LC880 as follows 1 Using the Trigger software open an existing experiment file or create a new file 2 In Trigger 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 LC880 s memory 4 Test your program by simulating triggers and examining the outputs using the LC880 s channel LEDs an oscilloscope or other diagnostic tool 5 Store variations of the channel properties in one of the 64 settings profiles in the LC880 6 Plug your experimental equipment to the LC880 7 Run the experiment using the LC880 by itself or leaving it tethered to the PC Switch between settings profiles during the experiment to handle or simulate various timing conditions Installing Trigger Software Insert the Trigger Software disk in the CD ROM drive and execute the setup exe file Setting Up the LC880 1 Plug the power cable from the back of the unit into a 110 250 VAC power outlet 2 Connect the 9 pin cable to the back of the LC880 and to
17. fines Globals x C cre To set up a channel s logic open the channel s Settings screen then click the Logic tab Type the logical statement in the large white box A typical logical statement may read inB not in2 This statement means Trigger Channel B when the signal at input 2 turns low drops below 0 2 Volts Once triggered the channel will function according to its timing properties see below You can employ compound arguments in logical statements such as inB not outC and in 2 This statement means Trigger Channel B when the output of Channel C is low while Input 2 is high Here s an example that s more complicated still inB inl or in2 and outC or outD Here Channel B requires a signal from Inputs or 2 combined with a signal from Channels C or D in order to trigger The following rules apply to logical statements Logic is case sensitive Use lowercase and capital letters as in the samples above Spaces matter Use spaces per the samples above If a logical statement consists of more than one line each line should end in a carriage return The last line of a statement must end in a semicolon Multiline comments should begin with and end with Single line comments can be started with 29 Many symbols can be written in shorthand to speed up the process of writing logic For example not in1 can be written in1 Refer to the lis
18. 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 Three additional buttons appear next to the tabs 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 This disable function is volatile all channels are re enabled on power up Enable restores channel functions following a temporary disable The front panel LED for that channel will glow to indicate the channel s status 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 13 troubleshooting your channel settings and implementing software control of experiments You can also force trigger a channel from the LC880 front panel See Running Experiments Force Trigger Quiescent States When you disable a channel its input will not change the output The quiescent state of a channel is the setting of its output when
19. front panel function requires that you select a channel or ALL channels and a function To select a channel click the channel button The channel LED will glow brightly as will the available Function buttons The ALL channels button will function similarly to select all channels You can now perform one of the front panel functions on that channel In the image below the F channel button has just been pressed The buttons for the four available functions Enable Disable Trigger and Reset glow yellow Performing a Front Panel Function Front panel functions can be accessed in one of two ways select a channel or ALL channels then choose a function select a function then choose a channel or ALL channels There is no significant difference between these two approaches In the image below the Enable button has just been pushed The channel buttons and the ALL channel button are lit Pressing one of these buttons will now enable the channel s 34 Enable Disable ALL Occasionally you ll need to abort an experiment in progress due to equipment problems etc The quickest way to shut down an experiment is to disable the inputs and outputs of the LC880 To do so click the Disable button then click a particular channel button or the ALL channels button The inputs and outputs for all channels will be immediately frozen Following a Disable command you can re enable the inputs and outputs by clicking the Enabl
20. gh until you depress the trigger 16 Clocked Pulse Stream Mode Channel B X Timing mode Clocked pulse stream Clock high duration Enable fio Us z Clock low duration Disable E Us i Reset Inverted output Notes Ronee Wrigg er In clock mode the output of the channel is a steady stream of pulses You control the pulse duration and the time between pulses The input to a clock channel does not affect its output The front panel LED for a clock channel will glow green when the output is low or red when the output is high NOTE Fora high frequency clock the LED will altemate between red and green so quickly that it willappearasa continuous pale green yellow or orange light As mentioned earlier the LC880 can operate in two clock modes hi resolution and low resolution see General Settings Clock In hi res mode the clock pulse and duration can range from 0 64 us to 52 4 ms in increments of 160 ns In low res mode pulse and duration can range from 30 1 us to 3 35 s in increments of 10 24 us Trigger automatically rounds entries to the nearest allowed setting To set the pulse duration select the timing units seconds microseconds milliseconds or nanoseconds from the pop up then enter the duration in the Clock high duration box To set the time between pulses select the units then enter the duration in the Clock low duration box A clock s quiescent state is normally low See
21. hannel LEDs Function Buttons Power LED Channel Buttons 4 Programmable Experiment Controller k 0 E r 3 O AML oa D 6 amp amp 6 amp B r tek BERENE a i hi J Mires a e The LC880 front panel controls begin with the Power button and Power LED in the upper left corner When you first press the Power button the LED will flash green and red while the system runs its initial diagnostics It will then glow a steady color When it glows a steady green the front panel is unlocked and accepting button pushes When it glows red the front panel is locked When the front panel is locked even the power switch is deactivated providing security against accidental mis setting or tampering The channel LEDs offer useful information about the state of each channel A green light typically indicates that the channel is ready to receive a trigger A red light typically indicates that the channel is in the process of triggering When a channel indicator is off the channel is disabled see Running Experiments Enable Disable Channels Some useful exceptions will be discussed in the Timing modes section below The All Channel LED shows the status for all channels A green LED indicates that the LC880 will respond to external inputs and that external outputs are active A red LED indicates that the LC880 will not respond to external inputs and that outputs are in a fixed and frozen logical state The Channel and Function Buttons w
22. hidden or displayed by clicking View gt LC880 General Settings The General Settings screen lets you control functions that affect all channels of the LC880 To reach this screen click the General Settings button or choose General from the Channel menu Disable Enable I O On occasion you will need to abort an experiment or quickly place all outputs to your equipment in a safe state Each of the tabs of the General Settings screen includes buttons that let you disable and enable all inputs and outputs to the LC880 With I O disabled input signals are ignored Each output will be held at either a logic low or logic high depending upon its channel properties We ll refer to the safe voltage that a channel produces when disabled as the quiescent state see Channel Properties Quiescent States To restore channels functions click the Enable I O button These functions are nonvolatile the enabled and disabled state are restored on power cycle You can also disable or enable inputs and outpus from the LC880 front panel see Experimenting Disable Enable All Lock Unlock Panel You may lock or unlock the front panel buttons using the Lock Panel and Unlock Panel buttons This ability comes in handy for example in embedded control applications where the LC880 should function only in stand alone or computer controlled modes When the panel is locked the LED next to the power
23. ignal 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 O and 2 147 483 647 To allow a channel to be triggered again after reaching the limit press the Reset button on the LC880 or choose Program gt Reset Channels in Trigger Trigger on input high Allows the channel to be repeatedly triggered while an input is high Trigger on rising input Sets the channel to be edge triggered 1 e an input signal that stays high will only trigger the channel once The front 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 yes or no remains red no more triggers accepted no glows green waiting for next trigger yes is off glows green when trigger goes low To try validated trigger mode 1 On the General Settings screen select 100 64 low resolution mode for Channels A and B 2 In Channel A s properties select Validated Trigger I
24. ing screen and select the Delayed pulse after trigger timing mode you ll learn about Delayed Trigger mode shortly 4 Select the Logic tab Enter the logical phrase inA not inl Then click OK With this logic Channel A will trigger when you depress the trigger button You ll learn all about Logic below 5 Now transfer the logic to the LC880 by clicking the Set All Channels button io 6 Plug an oscilloscope to Output A to observe the channel output Remember the output voltage will vary from 0to5 V 14 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 LC880 i NOTE tf you change a channel s properties closing the Settings screen will have the same effectasclicking Apply Clicking the OK button will also have the same effect Logic settings are sent and saved in the LC880 but any changes are not implemented on the LC880 until you click Set All Channels button on the Main screen or choose Program gt Program All Channels Program All Channels is the same as clicking Apply for all channels and then instructing the LC880 to update its logic programming The Cancel button cancels any edits made since the last time the Apply button was clicked and closes the dialog window Fixed Output Mode Timing mode Fixed output
25. lay 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 valid trigger until the channel is reset Check the box 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 as those for Delayed Pulse After Triggering mode Normal Skip N triggers Retrigger N times Trigger on rising input Trigger on input high 26 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 O and 2 147 483 647 To allow a channel to be triggered again after reaching the limit press the Reset button on the LC880 or choose Program 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 Alert host computer Sends a ping to the PC upon completion of the trigger cycle following trigger The front 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
26. lay until this button is cleared NOTE To switch from counter 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 1000 measurements per second NOTE When you first run the LC 880 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 23 The front panel LED for the counter will be green until 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 counter mode is always high To try the counter timer mode One good way to see the counter in action is to have it compare the outputs of two clock channels The counter will measure the difference between the successive pulses of the two channels 1 On the General Settings select Full high resolution clock mode Channels B and C will be our clocks We ll use odd delay and duration values for the clocks so that the difference between pulses will be obvious 2 On Channel B s properties tab select Clock mode Enter a delay of 54 ms and a duration of 79 ms Click 66 Apply 3 On Channel C s properties tab
27. menu or by pressing a button on the Main screen 1 Menu options The File menu lets you open close and save experiment files Trigger files bear a trg suffix The Edit Menu lets you cut copy and paste text as you edit your program The View menu lets you set up the Trigger interface Choose to display or hide the tool bars and status bar select the font used in Trigger and set up communications with the LC880 The Channel menu lets you open the screens for General Settings and for each of the eight channels The Program menu includes options for communicating with the LC880 You can send logic send properties reset all channels or enable disable the LC880 s inputs and outputs 2 The buttons are as follows 10 oe The Channel buttons open the Settings screens for all channels ABBRPEERBA updates the LC880 with all current settings The General Settings button opens the General Settings screen 1 The Program button RESET 2 The Reset button resets all channels of the LC880 Retriggering Counters and delay settings will be reset as well 3 The Main window panel shows a text summary of all of the settings that have been entered 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 At any time the LC880 control bar can be
28. n waiting for next trigger yes yes is off glows green once input goes low To try the delayed pulse mode Under General Properties choose 100 64 low resolution clock mode for Channels A and B 1 In Channel A s properties screen select Delayed Trigger 20 On the Delay tab enter a delay of 1 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 LC880 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 1 e the input signal is high the channel will continue to trigger until the limit 1s 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
29. nput mode 3 On the Validate tab enter a Minimum duration and Duration of output pulse of 1 second each 4 On the Triggering tab select Retrigger N times and set N 50 Click Apply to save the settings 5 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 for another input pulse 22 Counter Timer Mode Channel C X Timing mode Counter Timer J Logic Counter Last delay between input pulses 36 252570 ms g T Hold measurernent Disable Reset Ronee Wrigg er Seve measurements ta tile m Erwee The counter timer mode determines the time delay between two separate input signals with 10 ns resolution 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 counter see Channel Properties Logic below For example if the logic reads in1 and in2 the counter will determine the time delay between a pulse at Input 1 and the next pulse from Input 2 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 disp
30. ork as pairs you will select one of each to perform any function In the base state all buttons glow dimly indicating that they re ready for your instruction Once you press a channel or function button only the available options will be illuminated TRIGGER SOFTWARE INTERFACE Trigger has been designed exclusively for setup and control of the LC880 You ll use Trigger to set the timing properties and logic for each of the eight channels and to set up overall properties for the experiment Main Screen When you run Trigger you ll be greeted by the Main screen Untitled trigger Mel File Edit View Channels Program Help amp K AREDEBEBRES Overall LCAAN settings All channels using ternal 100 MHz time base Channel A Delayed pulse Delay after tigger 20 000000 us then pulse output 10 000000 us Triggering options Trigger on rising edge Unlimited retriggermy Trigger Input Logic m riot inl Channel B Delayed pulse Delay after tigger 20 000000 us then pulse output 10 000000 us Triggering options Trigger on rising edge Unlimited retiggermg Trigger Input Logic mB notin Channel C Delayed pulse Delay after tigger 20 000000 us then pulse output 10 000000 us zj No tasks remaining OK For Help press Fl From this screen you ll control or access all of Trigger s functions Most Trigger functions can be accessed in two ways by selecting an option from a pull down
31. output pulse the dynamic delay in Channel C will calculate the time difference 100 ms multiply it by 32 16 and subtract the 200 us offset 199 8 ms after receiving the signal from Channel B Channel C will send a 100 ms output pulse Ze 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 delay is lt 20 ns Channel E X Timing mode Toggled output Toggle output at each trigger Initial state Low Debie High Trigger OK Apply Cancel The only user settings for this mode are the initial state which may be either low or high The front panel LED for the channel will glow green when the output is low or red when the output is high Logic A channel s logic determines the combination of signals that will trigger the channel Signals from the eight inputs and outputs from the other channels can be combined to trigger any channel The Logic properties tab lets you set the triggering criteria for a channel This tab only appears for timing modes which can respond to logic 28 Channel B X Timing mode Delayed pulse after trigger Logic Delay l Triggering Sweep Combinatorial logic for trigger input Enable nE not ine Disable Trigger Prede
32. red setting case insensitive 3 Click Store 36 To Our Valued Customers Most Current User s Manual and Trigger Control Software To obtain the most up to date version of this user s manual and the Trigger Control Software please refer to our website at http www labsmith com Corrections to this user s manual and Trigger Control Software Please contact us at support labsmith com to report any information that is missing or errors in the user s manual or Trigger 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 Trigger and LC880 are trademarks of LabSmith Inc Windows 95 98 Me NT 2000 and XP are registered trademarks of Microsoft Corporation Adobe and Acrobat are registered trademarks of Adobe Systems Inc Trigger software 1996 2002 LabSmith This manual 2002 LabSmith No part of this document may be reproduced or distributed without the consent of LabSmith 37
33. rmation The LC880 includes eight TTL compatible inputs and eight TTL compatible 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 TTL highs The LC880 can be connected to disconnected from the PC at any time without damage to either unit This ability allows you to program to LC880 at your computer then to take the unit to the experiment area for stand alone use Basic Functions The LC880 provides eight 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 precise 100 MHz internal clock or an external clock allowing resolution down to 10 ns Each channel also includes logic settings which specify the conditions that will trigger the channel A channel can be triggered by any logical combination of signals from the eight inputs and or the outputs of other channels The timing properties and logic that you set up in Trigger can be transferred and stored in the memory of the LC880 You can store up to 64 variations o
34. select Clock mode Enter a delay of 87 ms and duration of 85 ms Click Apply 4 On Channel A s Logic tab enter inA outB and outC You ll learn more about channel logic in the Logic section below 5 On Channel A s Properties tab select Counter mode with milliseconds as the units Click Apply 6 Lastly click Send Logic on the Main screen to update the new logic for Channel A The time difference measurements should now appear in rapid succession in the Last Measured Period box on Channel A NOTE The LC 880 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 24 Dynamically Delayed Pulse Mode The dynamic delay is the LC880 s piece de resistance 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 NOTE The dynamic delay is particularly useful for ballistics or gas dynamics expenments in which the velocity of a projectile or wave must be calculated and used to time the tnggenng of an expenmental device The Dynamically Delayed pulse includes several properties tabs
35. t 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 a A green light on a channel typically indicates that the channel is waiting for an input trigger When a channel is in Fixed Output Clock Pulse Output Input or Toggled timing modes the green light indicates that the output is currently LOW for that channel b A red light typically indicates that the channel is in the process of triggering When a channel is in Fixed Output Clock Pulse Output Input or Toggled timing modes the red light indicates that the output is currently HIGH for that channel c 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 NOTE Channel LEDs provide important information about the channels but an oscilloscope remainsa useful tool fordiagnosing channel outputs partic ulany for high soeed expenments ALL Channel LED The All Channel LED shows the overall status of the channels A green LED indicates that the external inputs and ouputs are enabled and functioning normally A red LED indicates that the external inputs and outputs are frozen See Running Experiments Disable Enable channels below 33 Selecting a Channel from the Front Panel Each
36. t below for other shorthand characters The following symbols can be used in logical statements Symbol Shorthand not and amp or vertical line xor HIGH none LOW none none none Predefined Vanables To speed logic coding we ve predefined a number of Predefined variables inA inH the input of channels A through H These signals only appear internally at the input of the timing channel they are not connected to the rear BNCs These symbols can only be on the left hand side of an assignment for example inA outB is valid but inA inB is not inl in8 inputs through 8 from the rear BNC connectors outA outG outputs of channels A through G that appear at the rear BNC connectors NOTE The output of channel H is not intemally connected to the logic processor It cannot be used in logic statements unless it is extemally connected to another channel input LOW FALSE trigger input always low HIGH TRUE trigger input always high To view the variable names that are recognized by Trigger click Predefines on the Logic tab The following dialog box opens Predefined symbols and operators a Symbols Logic operators car be entered in text or symbole Form New local or global aymboals can be defined for example tigger Ind and ling 30 Double click a variable to copy it to your Logic statement You can also select the variable then click
37. tore Recall Settings Profiles INTRODUCTION The LC880 is a fully programmable logic and timing controller for coordinating and synchronizing lab equipment and physical experiments LC880 provides clocks counters triggers and many other useful functions with 10 ns resolution and 100 ps accuracy As you are well aware controlling and synchronizing your 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 LC880 simplifies your control setup so you can go about the business of gathering data and making knowledge The LC880 consists of two components Trigger software and the LC880 experiment controller Trigger lets you design and run experiments from a simple graphical interface The LC880 controller provides the connections and control for your experimental devices Parts List Your LC880 package should include the following items 1 the LC880 controller 2 AC power cable 3 Trigger software installation CD 4 9 pin RS232 cable 5 User s manual If any parts are missing or damaged please contact LabSmith support Specifications Trigger software will run on any PC compatible computer running Microsoft Windows 95 98 Me NT 2000 or XP Drivers for National Instruments Lab View software are also available for download See http www labsmith com for more info
38. utton fee or choose Program gt Program All Channels While the logic is transferring the Power LED on the LC880 will turn red Logic transferring typically takes only a second though it may take slightly longer for complex programs After the transfer the logic settings reside in the LC880 even if you turn the unit off or disconnect it from the PC 32 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 trg 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 Trigger Click Send Properties then click Send Logic to download the settings to the LC880 You can also choose Program All Channels and Program Logic from the Program menu To print a text summary of the settings in the current experiment choose File gt Print Front Panel Controls and Indicators The front panel of the LC880 is designed to help you run experiments without computer control This functionality allows you to program the uni
39. 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 On the General Settings screen select 100 64 low resolution mode for Channels C and D and optionally for Channels A and B 2 On Channel A s Properties tab select Output Input mode 3 On Channel A s Logic tab enter inA not in 4 On Channel B s Properties window select Delayed Trigger mode with a delay and duration of 100 ms each Setup for edge triggering and allow retriggering 5 On Channel B s Logic tab enter inB outA This logic will cause the delayed trigger to pulse 100 ms after a signal from Channel A 6 On Channel C s Properties window select Dynamically Delayed Pulse mode Set up for scaling by 2 where N 1 and set the Added Delay to 200 s and the duration to 100 ms Allow unlimited retriggering 7 Since you ve made changes to multiple channels go to the Main screen and click the Set All Channels button All of your changes will now be stored in the LC880 Now the test is ready Depress and hold the trigger button Output A will transition high causing the delayed trigger in Channel B to begin its count When Channel B sends its
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