Trigger Delay Model (Grablink Duo)

Elaboration of the Camera Trigger event

Three functional blocks are involved in the elaboration of the Camera Trigger event:

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The GPIO Input port receiving and cleaning the electrical signal

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The I/O Toolbox tool(s) receiving the cleaned signal and delivering the cycle trigger event to the CIC

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The Camera and Illumination controller

NOTE:

the Camera Trigger event is recorder by Memento and time-stamped with 1 MHz clock.

GPIO Input Port — GPIO_IN delay

The delay introduced by the GPIO Input port depends on:

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The electrical type

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The settings of the associated digital filter

The following table shows the typical GPIO-IN delay values with the lowest digital line filter strength:

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Δton/high is the delay value at the low-to-high transition of the input signal or when the optocoupler turns ON.

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Δtoff/low is the delay value at the high-to-lowtransition of the input signal or when the optocoupler turns OFF.

GPIO electrical type	Δton/high	ΔtOff/high
Differential Input (Version 1)	50 ns	50 ns
Differential Input/Output	50 ns	50 ns
TTL Input/Output (Version 2)	50 ns	50 ns
TTL Input/5 V CMOS Output	50 ns	50 ns
Isolated Input (Version 2)	0.8 µs	1.35 µs

See also: Line Filter Control for other settings of the digital filter.

I/O Toolbox — TBX delay

The delay introduced by the I/O toolbox depends on its configuration:

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There are no significant delay when the LIN tool is driving directly the CIC Cycle Trigger.

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A constant delay can be introduced when a DEL tool is involved in the generation of the CIC Cycle Trigger event.

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An unpredictable delay can be introduced when DIV and MDV tools are involved in the generation of the CIC Cycle Trigger event.

See also: I/O Toolbox for a detailed description of the I/O Toolbox tools

Camera and Illumination Controller — CIC delay

The delay introduced by the Camera and Illumination Controller depends on its configuration:

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There are no significant delay when StrobeDelay is 0 or > 0 providing that the conditions to start a cycle are all satisfied.

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When StrobeDelay is negative, the Camera Trigger is delayed accordingly.

See also: Camera and Illumination Control and CIC Timing Diagrams

Transmission of the Camera Trigger event- CL Delay

Two functional blocks are involved in the transmission of the Camera Trigger event:

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The CCx line driver inside the 1628 Grablink Duo card

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The CCx line receiver of the camera

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These LVDS devices exhibit don't introduce significant delay.

The delay introduced by the medium is usually not significant!