Rebuild of Operator TrgPortLine with VisualApplets Signal Processing Operators

Brief Description

File: \examples\Processing\Trigger\mE4VD4-CL\Line\TrgPortLineRebuild_mE4VD4CL.va

Default Platform: mE4VD4-CL

Short Description

VisualApplets operator TrgPortLine is rebuild with other signal processing operators from the VisualApplets operator libraries. The rebuild allows you custom trigger functionalities and shows the usage of many signal processing operators in VisualApplets.

Operator TrgPortLine is a complex VisualApplets operator which offers a wide range of line scan trigger functionalities. In some applications it is required to have a modified functionality of this operator for custom signal processing.

In this example, we present a rebuild of the TrgPortLine operator with other VisualApplets signal processing operators. This enables you to adapt and modify the functionality to your custom requirements. The implementation is advanced but easy to understand. To simply the complex parameterization of the implementation, the following translation table helps you to calculate the parameters of the new design based on the parameternames of the TrgPortLine parameters.

Name YOffset
Default 0 
Device1_Process0_ImageTrigger_ImageHeight_Width = YHeight - YOffset
										Device1_Process0_ImageTrigger_ImageTriggerDelay_Delay_Delay = YHeight + YOffset
Name YHeight
Default 1024 
Device1_Process0_ImageTrigger_ImageHeight_Width = YHeight - YOffset
										Device1_Process0_ImageTrigger_ImageTriggerDelay_Delay_Delay = YHeight + YOffset
Name LineTriggerMode
Default GrabberControlled 
Device1_Process1_LineTrigger_LineTriggerMode_Select = 3 if GrabberController 0,1 or 2 if Extern_Trigger
										For Extern_Trigger, the correct value is defined by the shaft encoder settings.
										The other modes available by TrgPortLine are not supported.
Name ExsyncEnable
Default OFF 
Device1_Process1_LineTrigger_Exsync_ExsyncEnable_Select = 1 if ON  0 if OFF
Name LineTrgInSourceA
Default 0 
Device1_Process1_LineTrigger_TraceA_Input_Select = LineTrgInSourceA
Name LineTrgInSourceB
Default 1 
Device1_Process1_LineTrigger_TraceB_Input_Select = LineTrgInSourceB
Name EncoderABMode
Default Signal_A_Only 
Device1_Process1_LineTrigger_LineTriggerMode_Select = 3 if LineTriggermode == GrabberControlled
	  									0 if EncoderABMode == Signal_A_Only 1 else Device1_Process1_LineTrigger_ShaftEncoder_Mode =
	  									Mode1X if EncoderABMode == Signal_AB_Filter
	  									Mode2X if EncoderABMode == Signal_ABx2_Filter
	  									Mode4X if EncoderABMode == Signal_ABx4_Filter
Name EncoderABLead
Default Signal_AB 
Device1_Process1_LineTrigger_ShaftEncoder_LeadingTrace =
	 									A if EncoderABLead == Signal_AB
	 									B else
Name LineTrgInPolarity
Default LowActive 
Device1_Process1_LineTrigger_TraceA_Polarity_Invert =
	  									Invert if LineTrgInPolarity = LowActive
	  									NotInvert else
Name LineTrgInPolarity
Default LowActive 
Device1_Process1_LineTrigger_TraceA_Polarity_Invert =
	  									Invert if LineTrgInPolarity = LowActive
	  									NotInvert else
										Device1_Process1_LineTrigger_TraceB_Polarity_Invert =
	  									Invert if LineTrgInPolarity = LowActive
	  									NotInvert else
Name LineTrgDownscaler
Default 1 
Device1_Process1_LineTrigger_Downscale_Donwscale = LineTrgDownscaler
Name LineTrgPhase
Default 1 
Device1_Process1_LineTrigger_Downscale_SelectecPulse = LineTrgPhase
Name ExsyncPeriod
Default 100µs 
Device1_Process1_LineTrigger_Generate_Period = ExsyncPeriod / TClk
Name Exsync2Delay
Default 0µs 
Device1_Process1_LineTrigger_Exsync_Exsync2_Delay = Exsync2Delay / TClk
[Note] VisualApplets Version 2.1 or Higher Only

The delay has to be set to 0 for VisualApplets version 2.0.

Name ExsyncPolarity
Default LowActive 
Device1_Process1_LineTrigger_Exsync_OutputPolarity_Polarity =
	 										Invert if ExsyncPolarity = LiwActive
											NotInvert else
Name ImgTriggerMode
Default FreeRun 
Device1_Process0_ImageTrigger_SelectGatedImageTrigger_Select =
											1 if ImgTriggerMode == FreeRun
	 										0 else
											Device1_Process0_ImageTrigger_SelectFreeRun_Select =
	  										1 if ImgTriggerMode == FreeRun
	 										0 else
Name ImgTriggerInSource
Default InSignal0 
Device1_Process0_ImageTrigger_EnableSoftwareTrigger =
	  										1 if ImgTriggerInSource == SoftwareTrigger
	 										0 else
											Device1_Process0_ImageTrigger_ImageTriggerInput_Input_Select =
											  0 if ImgTriggerInSource == InSignal0
											  1 if ImgTriggerInSource == InSignal1
											  2 if ImgTriggerInSource == InSignal2
											  3 if ImgTriggerInSource == InSignal3
											  4 if ImgTriggerInSource == InSignal4
											  5 if ImgTriggerInSource == InSignal5
											  6 if ImgTriggerInSource == InSignal6
											  7 if ImgTriggerInSource == InSignal7
Name ImgTrgInPolarity
Default LowActive 
Device1_Process0_ImageTrigger_ImageTriggerInput_Polarity_Polarity =
										  	Invert if ImgTrgInPolarity == LowActive
										  	NotInvert else
Name ImgTrgDelay
Default 0 lines 
Device1_Process0_ImageTrigger_ImageTriggerDelay_Delay_Delay = ImgTrgDelay
[Note] VisualApplets Version 2.1 or Higher Only

The delay has to be set to 0 for VisualApplets version 2.0.

Name FlashEnable
Default OFF 
Device1_Process0_ImageTrigger_FlashOutput_Enable_Select =
											1 if FlashEnable == ON
											0 else
Name FlashPolarity
Default LowActive 
Device1_Process0_ImageTrigger_FlashOutput_Polarity_Polarity = 
											Invert if FlashPolarity == LowActive
											NotInvert else
Name FlashDelay
Default 0 lines 
Device1_Process0_ImageTrigger_FlashDelay_Delay_Delay = FlashDelay
[Note] VisualApplets Version 2.1 or Higher Only

The delay has to be set to 0 for VisualApplets version 2.0.

Name SoftwareTrgPulse 
Device1_Process0_ImageTrigger_SoftwareTrigger_Mode = 
	 										Pulse if SoftwareTrgPulse == 1 && ImgTrgMode == ExternSw_Trigger
	  										not write access else
Name SoftwareTrgInput 
Device1_Process0_ImageTrigger_SoftwareTrigger_Mode = 
											High if SoftwareTrgInput == 1 && ImgTrgMode == ExternSw_Gate
	  										Low else
Name ImgTrgIsBusy (read only parameter) 
ImgTrgIsBusy = Device1_Process0_ImageTrigger_ImgTrgIsBusy_Status
Name CC1output
Default Exsync 
Device1_Process1_LineTrigger_Exsync_CC1_Select_Select = 
											0 if Exsync
											1 if ExsyncInvert
											2 if Exsync2
											3 if Exsync2Invert
											4 if Flash
											5 if FlashInvert
											6 if Gnd
											7 if Vcc
Name CC2output
Default Exsync 
Device1_Process1_LineTrigger_Exsync_CC2_Select_Select = 
											0 if Exsync
											1 if ExsyncInvert
											2 if Exsync2
											3 if Exsync2Invert
											4 if Flash
											5 if FlashInvert
											6 if Gnd
											7 if Vcc
Name CC3output
Default Exsync 
Device1_Process1_LineTrigger_Exsync_CC3_Select_Select = 
											0 if Exsync
											1 if ExsyncInvert
											2 if Exsync2
											3 if Exsync2Invert
											4 if Flash
											5 if FlashInvert
											6 if Gnd
											7 if Vcc
Name CC4output
Default Exsync 
Device1_Process1_LineTrigger_Exsync_CC4_Select_Select = 
											0 if Exsync
											1 if ExsyncInvert
											2 if Exsync2
											3 if Exsync2Invert
											4 if Flash
											5 if FlashInvert
											6 if Gnd
											7 if Vcc
Name ImgTrgDebounceMaxTime
Not Required in this implementation.
Name ImgTrgDebouncingTime
Default 65.520µs 
Device1_Process0_ImageTrigger_ImageTriggerInput_Debounce_Debounce = ImgTrgDebouncingTime / TClk
Name LineTrgDebouncingTime
Default 0.112µs 
Device1_Process1_LineTrigger_TraceA_Debounce_Debounce = LineTrgDebouncingTime / TClk
											Device1_Process1_LineTrigger_TraceB_Debounce_Debounce = LineTrgDebouncingTime / TClk

The variable TClk depends on the frame grabber used. For the microEnable IV VD4-CL, the period is 16ns. Check Appendix. Device Resources for a complete list.

Implementation

The implementation is divided into the two parts ImageTrigger and LineTrigger. The LineTrigger implementation is located in Process1. As this process has no DMA channel, it will be immediately started after loading the applet to the frame grabber even when the acquisition is not started, yet. This has the advantage, that the camera can already be triggered before the acquisition is started. See 'Processes without DMAs / Trigger Processes' for more information on processes without DMA channels.

The next two sections will outline the implementations of the image trigger and line trigger.

Image Trigger Implementation

The image trigger part is responsible to assemble the image i.e. to form 2D images from the 1D input line stream. In accordance to operator TrgPortLine the image height can be defined by either a fixed height and usage of all input lines (free run), a fixed height but external controller image start (external or software trigger) or the height can be defined by the pulse length of an external or software trigger signal (gated mode).

The main part of the image trigger implementation is the SignalGate operator. The image height is defined by the time the gate is open. Module ImageHeight (operator SignalWidth) defines the height in the free run or edge controlled trigger modes. In these cases, the operator value is increases with every new input line. This is a good example where the Tick input is used for controlling the counting speed. In the free run mode, a new image is started immediately after the previous one is finished i.e. the SignalWidth operator is finished with the output of its period. In the external or software trigger mode, a new image is started with a rising edge at the input of the SignalWidth. The RS-FF is required to ensure a sufficiently long enough pulse.

With SelectGatedImageTrigger the implementation can be switched to the gated mode, where the pulse length controls the image height.

The hierarchical box NOP_DelayChain includes some NOP operators. These operators are required to delay the input signal a few clock cycles. This is required as the calculation weather the gate has to be opened or closes requires some clock cycles. VisualApplets cannot perform an automated pipeline adjustment in this case. Therefore the delay is required.

Hierarchical Box ImageTrigger of the TrgPortLine Rebuild Example

Figure 415. Hierarchical Box ImageTrigger of the TrgPortLine Rebuild Example


Other parst of the implementation comprise the input output output signal generation. The implementation of these parts is simple and straight forward. The flash output signal is transfered to Process1 using a TxSignalLine operator in h-box FlashOutput. This is required as the flash signal has to be output to the CC signals as well.

Line Trigger Implementation

The LineTrigger hierarchical box mainly consists of the input and output signal generation as well as the shaft encoder analysis and frequency generator. For the shaft encoder signal analysis operators ShaftEncoder, ShaftEncoderCompensate are used. The Select switch LineTriggerMode allows for an individual selection if the compensation or two trance analysis is enabled or disabled. Moreover, an internal frequency generator represented by a Generate operator is implemented to trigger the camera.

Hierarchical Box LineTrigger of the TrgPortLine Rebuild Example

Figure 416. Hierarchical Box LineTrigger of the TrgPortLine Rebuild Example


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