I have been tracking the recent post on GPS multiplex!! Here is another observation from a partner currenlty engaged in qualifying their application/environment on an MC75A:
"We are still experiencing some issues with our navigation software, and have noticed some odd behavior that we feel may be device related.
Last week, while attempting to set up the comm port manually, we had issues reading GPS data from (this is after you and I repaired the device through a clean boot) We were eventually able to get it working after talking to our vendor by selecting the option to scan for the GPS port.
The issue we are having is as follows
If I launch the navigation app while I am not in satellite coverage, the app will freeze and not recover. If I launch the app while I am in satellite coverage, it will launch and operate as I expect without issue
The interesting part in all of this is that I notice the exact same behavior when using the Bee Line GPS application we tested with while you were here. If I have satellite lock when I launch it and it scans for the port, life is good. If I launch it when I do not have satellite coverage, it gets locked up during searching
The coincidental behavior between the two different programs is leading us to think that perhaps there is something going on at the device level. We are interested in any thought you had on these findings" I am currently testing to confirm this behaviour!! I welcome any feedback on GPS on the MC75A!! Thanks in advance, Don
4 Replies
Thanks for the response Chi Zhang. To note, when we first encountered the issue we took and "out-of-box" approach. Clean-booted the unit and started fresh!! Here is the last communicaiton from the partner working with the MC75A:
"Hi Don, I have some more details - I have been testing all morning to try to narrow it down
What I have been able to determine is that when the device does not have satellite visibility (see notes below on this) that when a program is attempting to connect to the serial port (all programs discover COM8 4800), it will hang and not recover. I have confrmed this using 3 different programs, visualGPS, BeeLineGPS and our integrated application, Telogis/GeoBase
The device itself does appear to continue to operate, however with our integrated app which is full screen, we are not able to exit it to verify this (as it is frozen). All 3 applications fail to recover if the device is placed into satellite view.
The same 3 programs, if there is access to any satellites, operate as expected.
Satellite Visibility Notes
Testing this initially was giving random results as it is hard to know if the device can acquire GPS signal or not, and in the office it was giving intermittent results. To verify this was the cause, I used an RF shielding enclosure to block any signals. Testing with satellite signals was performed outside in clear view. This allowed me to get consistent results for the two conditions" I am about to initiate my own testing to confirm this. Don
Don, any update on your testing? I am also have similar issues.
Team Any resolution for the GPS issue ?
Please don't touch the settings in the "External GPS". Use whatever it is out of the box. Are you using the COM8? Or did you ask the application to try different COM port till seeing the NMEA data? If it's the later case, then it's possible that your app happens to open certain Vitual com port of BT or other device which have a long time out or didn't handle things well. Please use COM8 across all the MC products for GPS. With the maintenance release MC75A (maybe Oct), the 'hardware port' will be changed from 'GMX1' to 'COM2'. Then besides COM8, you have the option of using COM2 as well (currently GMX1 is also a choice, if you like the name). Except that COM2 is not a multiplexing port.