Example: Alternating Exposure Between Sensors - Dalsa Z-Trak2 2K Series User Manual

Recall:
•
Secondary (slave): device whose Trigger Start Source parameter is always set to multi-sensor sync.
•
Primary (master): device whose Trigger Start Source parameter is not set to multi-sensor sync. The primary
generates the messages that synchronize the secondary sensors.
Parameters
Laser Activation
Exposure Time
Sync Mode
Sync Status
Sync Group
Sync Group Delay
Sync Group Delay Mode
Trigger Mode Selector
Trigger Enable
Trigger Start Source
Trigger Delay
Profile Trigger Frequency, Current
Profile Rate
Line Selector
Line inverter*
* An external signal is detected only with a rising edge.

Example: Alternating Exposure Between Sensors

When the measurement areas of sensors overlap, it is necessary to alternate the sensors' exposures to prevent
interference between laser lines with same color lasers (see Figure 31).
Suppose you have to alternate exposure between two sensors and need to reach a 1 kHz profile rate (i.e., the
time between profiles is 1000 µs), then exposure for each sensor must be set to 1000 µs ÷ 2 = 500 µs or less.
The first sensor can expose for 500 µs with no exposure delay; the second sensor must have a delay of 500 µs
and then expose for 500 µs.
The alternating exposure mode is available when Trigger Mode Selector is set to Profile Trigger.
In the example below, exposure time was set at 500 µs for both profilers. A trigger delay for the sensor named
Secondary was set at 500 µs. Exposure time and trigger delay values are only used as examples.
Z-Trak Family of 3D Sensors
Sequential Exposure
(alternating exposure between sensors)
Primary Settings Secondary Settings
Strobed Strobed
User defined User defined
On On
Primary Secondary
1 1
Set by user Not Enabled
Set by user Not Enabled
Profile Trigger Profile Trigger
Off (internal) On
On (external)
Depends on Trigger Multi-sensor sync
Enable parameter.
If Off, the internal
clock is used to trigger
acquisition at the
specified Profile Rate.
If On, various sources
can be used, including
counter, timestamp
modulo, encoder, etc.
Set by user (if Profile Set by user
Trigger is On,
otherwise not enabled)
Depends on Trigger Depends on Trigger
Start Source Start Source
Set by user Set by user
Set by user Set by user
Teledyne Vision Solutions
Simultaneous Exposure
(exposure of all sensors together)
Primary Settings Secondary Settings
Strobed Strobed
User defined User defined
On On
Primary Secondary
1 1
Set by user Not Enabled
Set by user Not Enabled
Profile Trigger Profile Trigger
On On
Various sources can Multi-sensor sync
be used, including
counter, timestamp
modulo, encoder, etc.
Set by user Set by user
Depends on Trigger Depends on Trigger
Start Source Start Source
Set by user Set by user
Set by user Set by user
Multi-Sensor Systems • 69