I am sorry but I am not sure where to post this. I have an allsky-340 camera system. When I run the SBIG supplied software it works just fine. When I try using my python scripts and send the Checksum command "E", I get a return of ":" which is telling me that "failed transaction due to bit error during checksum transfer:". Any idea what the problem might be? cheers, Dan Klinglesmith Magdalena Ridge Observatory New Mexcio Tech
Doug, I have done a factory reset to 9600 baud. I am looking at allsky-340 manual from July 2009 V1.01. I am a little confused about sending commands. Do all of the commands end with a ":"? For example which is right "E" or "E:" to do the checksum example? cheers, dan
E: is correct. I assume you are following http://diffractionlimited.com/wp-content/uploads/2016/05/SG4_AllSky-340_SerialSpec.pdf
yes that is the manual I am using. Do all of the commands end with the ":"? The manual does not imply that. cheers, dan
The ":" is the checksum. Examples from the protocol document: Checksum Example Single Byte Command Command: “E” = 45h Inverse of 45h = BAh Checksum = 3Ah = “:” Successful Transaction: Sent: “E:” Received: “:O” Failed Transaction due to bit error during “E” transfer: Sent: “E:” Received: “>” Failed Transaction due to bit error during checksum transfer: Sent: “E:” Received: “:”
Yes, the checksum is there to protect the message against data errors. It has to match the command. https://en.wikipedia.org/wiki/Checksum
