AxioCam
Zeiss AxioCam MR/HR Adapter
| Summary: | Interfaces Zeiss AxioCam medium resolution and high resolution color and monochrome cameras |
| Author: | Henry Pinkard |
| License: | Source code cannot be made available |
| Platforms: | Windows |
| Devices: | AxioCam MRm/MRc/HRm/HRc, MRm/MRc/HRm/HRc Rev. 2, and MRm/MRc/HRm/HRc Rev. 3 (tested with MRm Rev. 2, MRm Rev. 3, MRc Rev. 3, HRm Rev. 2, HRm Rev. 3) |
Because of built in delays in the AxioCam's image acquisition, there is a delay of approximately 200ms between when Micro-Manager sends the command to open the shutter and when the AxioCam's exposure begins. If over exposure of the sample is a concern, it is highly recommended that hardware triggering is used with these cameras. Refer to the below descriptions of hardware triggering to do so (All images and text below ©2010 Carl Zeiss MicroImaging GmbH. All rights reserved.).
Trigger-Out
Via a supplementary cable the AxioCam has the capability of sending out a TTL trigger pulse to an external device, for example a mechanical shutter. This trigger pulse can be used to synchronize the exposure of the camera and the task of the external device, as you can specify the delay between sending out the trigger signal and actually starting the acquisition.
To meet the requirements of the device you are using, you can invert the polarity that you want the signal to have.
Trigger-In
The exact time of exposure can be triggered from outside the camera. When the trigger-in is enabled and an acquisition function is called, the camera will delay the acquisition and wait for a trigger-in signal to be sent from an external device until it invokes the exposure.
The following graphic demonstrates the two camera models' reaction to the trigger signal when performing a triggered acquisition. An acquisition request is sent out at each T, the acquisition takes place at an A:
NOTE: The trigger OUT of the AxioCam HR / MR expects a TTL signal.
Trigger Timing
Due to different hardware and trigger mechanisms, the precise calculation of the camera's timing when involvong the trigger IN / OUT is a bit difficult and depends on the camera model's internal design.
The following charts demonstrate, how an example acquisition using both trigger IN and trigger OUT could look like and explain how to precisely calculate the timing.
| AxioCam HR / MR |
| The AxioCam HR / MR accepts only positive values for the trigger OUT delay, ranging from 0 to 255 row cyles,
where 1 cycle lasts 154 µs (AxioCam HR) respectively 99 µs (AxioCam MR).
|
| AxioCam MRc5 / MR Rev.3 / HS |
| The AxioCam MRc5 / MR Rev.3 / HS allows both positive and negative values for the trigger OUT delay, ranging from +4095 row cycles
to -4095 row cyles, where 1 cycle lasts 244 µs. |
| - negative delay |
| If the specified trigger OUT delay is longer than the interval for the fixed idle rows and clearing the sensor,
the trigger OUT is sent directly after the initialization has been completed. The camera performs the cleanout
and then waits an appropriate amount of time until the exposition is invoked.
|
| If the specified trigger OUT delay is shorter than the interval for the fixed idle rows and clearing the sensor,
the camera starts the sensor cleanout right after the initialization was finished and delays sending the trigger
OUT signal to achieve the desired trigger OUT delay.
|
| - positive delay |
|
--Henry Pinkard 10:58, 2nd January 2013 (PDT)
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