Guys, Sorry to post again, but it just dawned on me that I meant to post some info concerning M12+, M12, GT, UT+, and probably even VP receivers. This issue is one of the reasons the M12M is late coming out of the chute. If I have posted this before I apologize. Just too many things rattling around in my brain.
CRITICAL: Whenever you run a Self-Test on any of these receivers, MAKE ABSOLUTELY SURE that you wait until you have gotten the response message before you issue any additional commands. If you get REALLY lucky and send your command at EXACTLY the wrong time while the UART is in limbo you can get stuck in a lovely "do...while" loop that can only be exited by cycling power to the receiver. A clue that this has occurred is that the 1PPS also stops. The Self-Test code in the M12M has been changed to keep this from happening. Looking back, this explains a lot of the unexplained random failures in cell towers reported over the years by a couple of the carriers. Absolutely unrepeatable. Almost impossible to troubleshoot. We just found it by accident. Now, before any of you wise guys try to repeat this problem, bear in mind that statistically it seems to happen maybe once per 200,000 Self Tests. Randy _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
