Control multiple (more than 2) ASI294MM Pro cameras simultaneously

JudyKim

By using SDK, I want to run the three ASI294MM Pro cameras simultaneously with one computer.
That is, if I give a command, three cameras start to give the same exposure at the same time and save the images with the different filenames.
(My final goal is controlling four cameras simultaneously)

Technical Support Engineer kindly gave me the comment as follows.
"Our SDK can only manage 2 camera connection at a time - you can however run multiple instances of the SDK"

What I'm thinking of is to make two identical C++ codes that control two cameras,
and run those two codes at the same time. In this way, I may be able to control maximum 4 cameras.

However, the problem is that one camera is connected multiple times.
That is if there are cameras 1,2 and 3
1th SDK connect camera 1 and 2
2nd SDK connet camera 1 (not camera 3!!!)

It seems that each camera does not have a unique number or name.
All cameras seem to ve recognized as ZWO ASI294MM Pro, so I can not specify them.
How can I solve this problem?

Also, do you think this method will work well without any crashes or conflict problems??
Any comments would be very very helpful.
Thank you so much.

Tech@ZWO

JudyKim You can use the 'ASISetID' function to tell the three ASI294

astromatto

JudyKim I am writing some new multiplatform drivers and the bit about 2 cameras scares me, do you mean that using libASICamera2.so allows to find and work only with two cameras at most?

JudyKim

astromatto Yes, as I understand the current device driver can control up to 2 cameras at once. Does 'new multiplatform drivers' mean you are writing the script that calls the libASICamera2.so to control the multiple (>2) cameras (i.e., What I am trying now)?

JudyKim

@tech@zwo#56576 Thanks for your comment!! This could be the solution. Let me try it and let you know the result.

astromatto

JudyKim not sure what you have in mind for "script" but I am writing a driver from scratch to control an undefined amount of ZWO cameras from a single program. I am storing all found devices in an array and issuing commands to the right camera based on the device id (this is not the ASI ID although it may be used as well), the code is completely open source anyway if you want to have a look

Tech@ZWO

The SDK does not limit the number of cameras to be controlled, but it does not support one command to control three cameras at the same time, one command can only control one camera.

astromatto

@tech@zwo#56622 thanks, makes sense

JudyKim

astromatto I cordially appreciate your kindness. It would be nice if I can look the source code! Where can I see the code?

JudyKim

@tech@zwo#56622 Hmm..I understand one command can only control one camera. 'The SDK does not limit the number of cameras to be controlled' means that it's fine if 'iNumofConnectCameras' is larger than 2 in the example code below? (I brought this example code from the document of 'ASICamera2 Software Developement Kit', ver. 2,8 and slightly modified it)

example code：
int iNumofConnectCameras = ASIGetNumOfConnectedCameras();
//In my case, iNumofConnectCameras = 3 because I connected 3 cameras
ASI_CAMERA_INFO ppASICameraInfo = (ASI_CAMERA_INFO) malloc
(sizeof(ASI_CAMERA_INFO )iNumofConnectCameras);
for(int i = 0; i < iNumofConnectCameras; i++)
{
ppASICameraInfo = (ASI_CAMERA_INFO *)malloc(sizeof(ASI_CAMERA_INFO ));
ASIGetCameraProperty(ppASICameraInfo, i);
camInitControl(i, &ASICameraInfo, &cinfo)
ASIOpenCamera(i);
ASIInitCamera(CamNum);
}

astromatto

JudyKim you can find the code at https://github.com/devDucks/asi-rs/tree/main/src/bin/ccd

I am still late with docs but that should come this week, to summarize (it works controlling 3 cameras) 😀
1) check how many cameras have been recognized
2) call GetCameraProperty for every device and store that data into a custom struct on the driver struct. The device is pushed to an array for this goal.
3) grab the Caps for every device and store them into the device struct
3) change props of whatever device by calling SetControlValue with an ID, the ID is something I added by myself and not present in the driver, in doing so I loop through driver.devices and when the ID matches I grab the camera index (this is returned by the SDK) so I know to which device I shall issue the SetControlValue

I can even shot exposure on all devices, my implementation leave the flexibility for the caller to implement what you wanna achieve

JudyKim

astromatto Thank you so so much for sharing your code and also your kind explanation 😄. The strategy you explained looks reasonable. Please give me time to check your code (This is my first to seeing rust code, but it looks good).

sm44

Hi there, I was wondering if you came up with a solution to simultaneously capture images on three cameras?