I'm using an STXL6303 with self-guider filter wheel on a 16" Meade LX200 ACF, all controlled by MaximDL 5 Pro. Have worked for years in this configuration. We seem to have a new problem: after finding a guide star, calibrating the guider on it, starting guiding, and setting up a series of exposures on a target, the guider fails after a few minutes, with a pop-up error box: "Guider Error (17)", and the guiding stops. Sometimes we get an hour of guiding before that happens, sometimes just a minute. We switched to guiding with a piggyback telescope with an SBIG ST-i, using the same HDMI cable to connect to the remote guide head port on the cameras, and guiding works fine for hours. Switch back to the internal guider on the filter wheel, and we get "Guider Error (17)" again. This makes me suspect a hardware problem with the guider on the filter wheel. Thanks for any advice!
Error 17 means "Shutter Error". That's weird, because the guide head doesn't have a shutter sensor - if the guider shutter doesn't work we don't hear about it. Have you updated the camera's drivers and firmware? If so MaxIm DL 5 might not understand it. We've made significant changes to the shutter management - the main camera and guide camera shutters are now completely independent. They weren't back in the day - they moved together. If you are running the old firmware, it's possible that there's an intermittent problem with the STXL's shutter. (Yeah that sounds weird but the old implementation was a bit odd... we changed all that after we acquired SBIG.)
One possibly related hint: When I start the guider auto guiding, I hear the shutter clicking for every guider exposure. But as soon as I start the science exposures with the main CCD in Autosave, the shutter stops clicking with each guider exposure, and starts clicking with each main CCD exposure. This was explained to us by SBIG folks years ago as the main CCD taking priority over a single mechanical shutter that served both the main camera and the guide camera, at which point the guider would switch to an electronic shutter. So I tried another test just now: I set the guider autoguiding but did NOT start a series of exposures with the main CCD. The autoguider still failed with "Guider Error (17)". *Should* I update the camera's drivers and firmware? How? Thanks, James
Back in the day people often used the built-in guide CCD, which is behind the main camera shutter. So of course the main shutter had to open when the guider took images if the main chip wasn't exposing. The shutter also had to close for the main camera readout, and then the guider would take over during the guider settling interval between main exposures, and then the main camera would start exposing and the shutter would stay open again. (Historical curiosity - that sequence was invented by me, based on how the original ST series cameras worked, many years before we acquired SBIG.) Of course modern cameras like the STXL don't have an internal guide chip! So that behavior is outdated. As part of our updating of the SBIG cameras, we have altered the firmware to decouple the two shutters. The guide head shutter responds to the needs of the guider, and the main shutter responds to the needs of the main camera. It shouldn't be a problem running the latest firmware with V5 but I don't believe that has been tested in-house. That said we've not had any complaints and it will probably work fine. Nevertheless, only the main camera's shutter can produce the Error 17. So there's something going on with your main shutter. Updating the firmware will make the guider exposures not actuate it, but that might just cover up what may be a developing problem with your main shutter. You may want to send the camera in to Bill for service.
