SG-4 subtle problems with USB - serial connection

I was having intermittent and incredibly annoying problems where, just as I was starting to get my SG-4 autoguider working programs start freezing. Using the SBIG SG-4 Interface software I could setup, test, expose, calibrate and (for awhile) track fine. Then out of the blue almost everything would work but if I tried "Start Autoguiding" the program would just freeze and become nonresponsive.

I chalked it up to perhaps some flakiness of the software on my hardware setup. I then got the guider working in MaximDL through the ASCOM driver, everything was working (though the guiding seemed to be jumping too much) and after I tried hitting "stop tracking" all of MaximDL froze (I'm running 5.12 currently).

Then I simply couldn't connect to the autoguider via either MaximDL or the interface software. When I tried connecting to the guider via interface software, I got a suspicious debug log(attached) that suggests windows really doesn't want to open COM5 where the guider is on. Resetting the computer seemed to allow me to connect again. I am going to try attributing this behavior to the serial to USB convertor, I'll pick up a FTDI US232R-10-BLK as the manual suggests; but I thought I'd ask if the driver devs have any insight or magic switches to help me solve my quite fragile interface to the SG-4 autoguider. I don't seem to see any firmware that I need to download if that is the cause.

 

Thanks again Colin!

 

Woohoo!
Using the US232R-10-BLK for the SG-4 and following Colin's advice on serial settings seems to fix the fragility of the connection to the autoguider. What a pathological thing to deal with, other USB to serial convertors work *for the most part*, they just blow up access to the COM port every 10 minutes or so.

A a quick question, I tried using the ASCOM interface to the SG-4 through maximDL. I followed the advice here:
https://diffractionlimited.com/help/maximdl/Autoguiding.htm
https://diffractionlimited.com/help/maximdl/Autoguider_Troubleshooting.htm

Using default settings and calibrating with maximDL etc. the guider seemed to be moving the haywire (the object moves out of field in under a minute). Using the supplied SG-4 software and turning guiding on that way I empirically get round stars in 10min exposures and the log file makes sense. I'm happy using the SG-4 specific software for now but it seems that MaximDL doesn't hook into the "push button"-ness of the SG-4 and uses it to guide like any other guiding camera. Is there a way to control the autoguiding from MaximDL to just make it easy to avoid having guiding on while slewing and letting things settle between exposures?

 

Ah so I can just leave it in guiding mode, watch the light for status, and not worry about the SG4 locking on a star mid slew and moving the scope around madly?