Canon - Device Busy w/ Flats

Hi guys,

Using the latest beta. Had an issue taking flats where short exposures (0.1 seconds) were generating a Device Busy error message with a Canon DSLR (T4i). I’m certain last time I was out I was able to do this, so not sure if anything has changed or this is just a transient error. Occurs just prior to 11:40pm (search for EDS_ERR_DEVICE_BUSY).

Thanks! (82.1 KB)

BH I am seeing this error with my regular images. I just posted this in the Canon Astro Yahoo group. Is any oneelse seeing this error?

I am imaging with a Canon 450D and Sequence Generator Pro. My last four sessions have ended with the following error: “Canon:Error in CameraComand_BulbStart (1) Error: EDS_ERR_DEVICE_BUSY” This seems to happen four or five images into the session. Pressing the OK button on the error message seems to clear the error and SGP moves on. But it does not allow me to leave the session unattended.
Is anyone familiar with this error. Any suggestions on how to prevent this in the future.

While I am unsure of the exact nature of your issue, I have changed this behavior to make it slightly less annoying for you (and likely others too). Canon errors now produce 'auto-dismissing" dialogs (after 5 seconds) so the sequence can attempt to continue (assuming it is not attended).

Thank you Ken. I posted on the Canon Astro group. If I here anything as to what the problem is I will post it.

This is actually a known issue since a post I made back in June:

I guess they haven’t corrected the error yet.

For what it is worth, I have this same problem with a Gary Honis modded T3i.

Using what version?

Thank you for the great software and quick response. My version is

OK. Well, if you are interested, the 2.4.1 beta (stable) has some code that tries to handle Canon device busy errors and also an option to software bin Canon AF frames (Canon settings dialog) to try and reduce the impact of the bayer matrix on the AF routine.

Thanks Ken - all these different setups must be frustrating to develop for.

I updated to the beta, but it didn’t solve my problem.

There are some fraction of a second values that work like 0.20; and some that error out like 0.30. Not sure if that is helpful, but I found it interesting.

I just can’t duplicate it to figure out what is wrong. I’ve attempted multiple times and I just can’t seem to make it happen. I certainly believe this is an issue as multiple people are experiencing it…

Believe me I certainly wish we could track it down! But without being able to duplicate the issue it’s difficult to fix :frowning:


I’m fairly certain I’ve fixed this. Should be out in the next beta. We were sending exposure times that the camera didn’t support. We’re now querying the camera for the exposures it supports and will map your value to those supported values. Which means in some cases you won’t get exactly the exposure you expect.

As an example my 60D Supports 1/100 and 1/160 but not 1/125. So if I enter an exposure of 1/125 (0.008) I’m going to get the next closest which would be 1/160 or 0.00625.

1/100 = 0.01
1/125 = 0.008
1/160 = 0.00625


Is this fix in v3.1.0.213? I don’t think so. Any long exposures from 1s and above cause timeouts. Short exposures < 1s work. How do I get a beta that includes the fix?