Operation with the "Always Active" Sequence Control Source

Operating the Sequencer

If the Always Active sequence control source is selected, the advance from one sequence set to the next proceeds automatically in ascending sequence set index numbers as frame start triggers are received.

The following use case (see also Figure 53) illustrates the operation of the sequencer in controlled sequence advance mode with Always Active selected as the sequence control source. As images are captured continuously, the camera advances automatically without any input from the user from one sequence set to the next in ascending sequence set index numbers. After one sequence set cycle is complete, another one starts.

This way of operating the sequencer feature is similar to operating it in auto sequence advance mode when each sequence set is used only once per sequence set cycle.

Here, however, the first sequence set used for image acquisition after the sequencer feature has been enabled is sequence set 1 as opposed to sequence set 0 in auto sequence advance mode.

Features AW00098506000

In this use case, the Sequence Set Total Number parameter is set to 6. Accordingly, the available sequence set index numbers range from 0 to 5. The frame start trigger is set for rising edge triggering.

Assuming that the camera is in the process of continuously capturing images, the sequencer feature operates as follows:

 When the sequencer feature becomes enabled, the sequence set cycle starts: the parameter values of the sequence set with sequence set index number 0 are loaded into the active set, thus modifying the active set.

When a frame start trigger is received, the camera automatically advances to the next sequence set: the parameter values of sequence set 1 are loaded into the active set and used for the image acquisition.

 When the next frame start trigger is received, the camera advances to the next sequence set:

the parameter values of sequence set 2 are loaded into the active set and used for the image acquisition.

 When the next frame start trigger is received, the camera advances to the next sequence set:

the parameter values of sequence set 3 are loaded into the active set and used for the image acquisition.

 The sequencer carries on cycling through the sequence sets. Note that the camera has completed a sequence set cycle when sequence set 5 has been used. With the next frame start trigger, a new sequence set cycle starts where sequence set 0 is used.

 After the sequencer feature is disabled, the cycling through sequence sets is terminated. The sequencer parameter values in the active set return to the values before the sequencer feature was enabled.

AW00098506000 Features

Fig. 53: Sequencer in Controlled Sequence Advance Mode with Always Active as the Sequence Control Source

Synchronous Restart

You can restart the sequence cycle with input lines Line 1, CC1, CC2, or CC3 as the source for controlling sequence cycle restart.

In the following use case (see also Figure 54), the same settings were chosen as in the previous use case: The Sequence Set Total Number parameter was set to 6. Accordingly, the available sequence set index numbers range from 0 to 5. The frame start trigger is set for rising edge triggering. In addition, Line 1 was selected as the source for controlling restart. Line 1 is not set for invert.

Assuming that the camera is in the process of continuously capturing images, the sequencer feature operates as follows:

 When the sequencer feature becomes enabled, the sequence set cycle starts: the parameter values of the sequence set with sequence set index number 0 are loaded into the active set, thus modifying the active set.

When a frame start trigger is received, the camera automatically advances to the next sequence set: the parameter values of sequence set 1 are loaded into the active set and used for the image acquisition.

0

1 2 3 4 5 0 1 2 3 4

0

Time

Frame Start Trigger Signal

= camera selects a sequence set as the current sequence set

= frame exposure and readout

= frame transmission

Sequencer Enabled

= current sequence set that is used for the image acquisition (the sequence set index number is indicated)

Sequence Set Cycle

Starts Again Sequencer

Disabled Use Case: Operation in controlled sequence advance mode with Always Active as the

sequence control source:

Automatic cycling through the sequence set cycles without input from the user. Enabling and disabling of the sequencer feature.

Settings: Sequence Set Total Number = 6

Frame start trigger is set for rising edge triggering

Features AW00098506000

 When the next frame start trigger is received, the camera advances to the next sequence set:

the parameter values of sequence set 2 are loaded into the active set and used for the image acquisition.

 When the next frame start trigger is received, the camera advances to the next sequence set:

the parameter values of sequence set 3 are loaded into the active set and used for the image acquisition.

 When the next frame start trigger is received, Line 1 is found to be high. Accordingly, another sequence set cycle is started and the parameter values of sequence set 0 are loaded into the active set and used for the image acquisition.

Note that the synchronous restart has priority here over the automatic sequence set advance that results from the Always Active sequence control source. Without the priority rule, sequence set 4 would be used.

 Note that the state of Line 1 goes high well ahead of the frame start trigger.

Note also that the camera briefly exits the "waiting for frame start trigger" status while the input line changes its state. This happens when input line 1 changes its state before the fourth frame start trigger is received (see also Figure 54).

 When the next frame start trigger is received, the camera advances to the next sequence set:

the parameter values of sequence set 1 are loaded into the active set and used for the image acquisition.

 When the next frame start trigger is received, Line 1 is found to be high. Accordingly, another sequence set cycle is started and the parameter values of sequence set 0 are loaded into the active set and used for the image acquisition. As explained above, synchronous restart has priority here over the automatic sequence set advance.

 When the next frame start triggers are received, the camera continues advancing from one sequence set to the next in ascending sequence set index numbers and using them for image acquisition unless another synchronous restart signal is received.

To ensure reliable synchronous sequence set restart, allow at least one microsecond to pass between the time when the signal of the sequencer trigger source has reached the high state and the rise of the frame start trigger signal.

Also, maintain the state of the input line for at least one microsecond after the frame start trigger signal has risen.

Make sure not to send a frame start trigger while the input line changes its state. During this period, the camera will not wait for a frame start trigger and any frame start trigger will be ignored.

Make sure to only send a frame start trigger when the camera is in the "waiting for frame start trigger" status.

For more information about the "waiting for frame start trigger" status, see the

"Acquisition Monitoring Tools" section on page 101.

AW00098506000 Features

Fig. 54: Sequencer in Controlled Sequence Advance Mode with Always Active as the Sequence Control Source and Synchronous Restart Controlled by Line 1

2

1 3 0 1 0 1 2 3 4

0 0

Use Case: Operation in controlled sequence advance mode with Always Active as the sequence control source:

Automatic cycling through the sequence set cycles with two synchronous restarts controlled by Line 1.

Setting: Sequence Set Total Number = 6

Line 1 (not set for invert) is selected as the source for controlling restart Frame start trigger is set for rising edge triggering

Signal Applied to Line 1 (Restart)

= frame exposure and readout

= frame transmission

= camera is waiting for a frame start trigger

= camera selects a sequence set as the current sequence set

= current sequence set that is used for the image acquisition (the sequence set index number is indicated)

Time

Frame Start Trigger Signal

Sequencer Enabled

Sequence Set Cycle Starts Again Sequence Set Cycle

Starts Again

Features AW00098506000