Bnc 725 User Manual

Berkeley Nucleonics Corporation Model 725 Multi-Trigger Digital Delay Generator User Guide Documentation for the Model 725 and timerPRO Software

10 Front Panel Controls The Model 725 front panel controls begin with the Power button and Power LED in the upper left corner. When you first press

11 SOFTWARE INTERFACE timerPRO has been designed exclusively for setup and control of the Model 725. You’ll use timerPRO to set the timing properties

12 1. Menu options: The File menu lets you open, close and save experiment files (.trg files). The Edit Menu lets you cut, copy and paste text as yo

13General Settings The General Settings screen lets you control functions that affect all channels of the Model 725. To reach this screen, click the

14 Lock/Unlock Panel Lock or unlock the front panel buttons using the Lock Panel and Unlock Panel buttons. This functionality is handy, for example,

15CHANNEL PROPERTIES Channel Properties Screen Each channel has a Settings screen in which you’ll select the timing mode, set the timing properties,

16 Channel properties are organized by tabs. The tabs that are relevant for a particular timing mode appear automatically when that timing mode is s

17Logic A channel can be triggered by any combination of signals from the eight inputs and/or other channel outputs. Channel logic determines the com

18 Logic Assignments The logic processor assigns the combination of external inputs (in1–in8) and channel outputs (outA–outG) that will trigger each

19It is important to distinguish between the eight physical input jacks, in1–in8, and the eight timing channel inputs. Any combination of the physica

20 Experimenting With Channel Logic This brief example will show you more about channel logic: 1. Connect a normally-open switch to Input 1 and ano

2112. Lastly, change the logic assignment to: inA = not in1 and not in2; 13. Click the Set All Channels button. The LED at Output A will remain of

22 - 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 t

23Global Variables “Local Variables” are those that are used directly in logic assignments, such as “inA” or “out1.” Logical assignments that are u

24 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 “

25Timing Modes In the previous section you learned that logic defines how channels are triggered. In this section you’ll use the Model 725 timing mod

26 Then click OK. With this logic, Channel A will trigger when you depress the external trigger button (connected via BNC cable). 5. Now transfer t

27Fixed Output Mode In this mode, the channel output remains in the selected state (Low or High), regardless of the input. The front panel LED for

28 Passive Mode (Output = Input) In passive mode, the output signal equals the input signal or its logical inverse. The front panel LED for the ch

29Clocked Pulse Stream Mode In clock mode, the output of the channel is a steady stream of pulses. You set the pulse duration and delay between puls

3TABLE OF CONTENTS INTRODUCTION 5 Parts List 5 Specifications 5 Basic Functions 6 How You Will Use the Model 725 6 Installing timerPRO Software

30 resolution mode, the clock pulse and duration can range from 0.48 µs to 52.4 ms. In low resolution mode, pulse and duration can range from 30.1 µ

31Delayed Pulse After Trigger Mode Upon receiving an input signal, a delayed pulse after trigger waits a specified delay time, then sends a pulse to

32 100 (high res mode) 100/64 (low res mode) Delay range 20 ns to 21.47 s 1.28 µs to 1374 s Duration range 7.7 µs to 21.47 s 493 µs to 1374 s

33reaching the limit, press the Reset button on the Model 725 or choose Program>Reset Channels in timerPRO. Trigger on rising input Sets the cha

34 To facilitate time-delay scanning experiments, the delay of the pulse relative to the trigger can be “swept” or incremented by a specified value

35A properties screen—the channel LED glows green and you can once again trigger the channel. 10. On the Triggering tab, choose Retrigger N times, s

36 Important Delay Timing Considerations Once the Model 725 has begun a delay sequence, it ignores incoming trigger pulses. There is also a delay of

37Validated Trigger Input Mode (Noise Suppression) The noise suppression function eliminates false triggers due to noise on the input signal by req

38 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 I

39To try validated trigger mode: 1. On the General Settings screen, select 100/64 (low-resolution) mode for Channels A and B. 2. Click OK to save

4 Experimenting With Channel Logic 20 Rules for Logical Assignments 21 Predefined Variables 21 Global Variables 23 Timing Modes 25 “Apply” vers

40 Timer Mode The timer mode determines the time delay between two separate input signals and reports it back to the PC. You can view the counter o

41 NOTE: To switch from counter mode, first click the Disable button and ensure the channel LED is unlit, indicating that the channel is d

42 6. On Channel A’s Logic tab, enter: inA = outB and outC; (You’ll learn more about channel logic in the Logic section above). 7. On Channel A’s

43Scaling In the calculation of the delay, the measured delay between two pulses is scaled by a factor of 2N, where –16 < N < 16, or N/16, wh

44 Delay Added Delay Set an offset value to subtract from the scaled delay length. This is useful when accounting for camera shutters or other la

45Triggering The triggering options are the same as those for Delayed Pulse After Triggering mode: Normal The channel can retrigger an unlimited nu

46 5. On Channel A’s Logic tab, enter: inA = not in1;. Click Apply. 6. On Channel B’s Properties screen select Delayed Pulse After Trigger mode. 7

47Toggled 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

48 several microseconds with temperature and aging. This drift may be relatively slow, but inconvenient to compensate. Dynamic Delay Compensation mo

49Desired delay The delay between the trigger and response signals that timerPRO will attempt to maintain. Duration of pulse The duration of the ou

5INTRODUCTION The Model 725 is a fully programmable logic and timing controller for coordinating and synchronizing lab equipment and physical experim

50 Channel C: Dynamic Delay Compensation: Delay: 2.000 ms; Duration: 10.000 µs Averaging: None (1 trigger) Trigger Input Logic: inC = outA |

51Channel B, which will provide a precision “delayed indicator” pulse. The delay of Channel B will be added to the “Desired Delay” of Channel C. On

52

53RUNNING EXPERIMENTS Once you’ve created a program you’re ready to set up and perform your experiment. Storing and Recalling Experiment Files As men

54 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

55 NOTE: Channel LEDs provide important information about the channels, but an oscilloscope remains a useful tool for diagnosing channel o

56 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

57Trigger a Channel This function lets you simulate an input trigger on a channel, regardless of the channel’s logic settings. This is a useful way t

58 To recall a setting profile from within timerPRO: 1. Choose Program > Recall Setting… 2. Click on or type in the desired setting (case insens

59GLOSSARY Apply Sends a channel’s current timing settings to the Model 725. Baud Rate The speed of communication via the Com port. Channel One of

6 Basic Functions The Model 725 provides eight functional channels, or internal signal paths. At any time, each channel can be assigned one of eigh

60 External Clock The “Ext Clk” input on the back of the Model 725 allows the time base to be controlled by an external source. Firmware The inter

61Predefines A set of standard variables and operators that can be used in logic assignments. Program All Channels A function which sends all logic

62 Trigger An input signal that initiates a channel function. timerPRO (software) The control software for the Model 725. Trigger Validation Mode

63 timerPRO and Model 725 are trademarks of Berkeley Nucleonics Corporation. National Instruments is a registered trademark of National Instrum

7Setting Up the Model 725 1. Plug the power cable from the back of the Model 725 into a 100–250 VAC power outlet. 2. Connect the 9-pin cable to th

8 Field Upgradeable Software The firmware in the Model 725 is field upgradeable, allowing access to new timing modes and capabilities as they become

9OVERVIEW OF MODEL 725 CONTROLS The Model 725 is the control unit and interface for your experimental equipment. You will program it using the timerP