2nd GPS strange behavior

I have installed the Emlid Reach M+ in our vtol for PPK use. The GPS output is connected to Gps2 (serial 4) of the pixhawk cube and I have configured the M+ to give GPS output in ERB format. I only want to use this GPS signal as redundancy for GPS 1.

But I get very strange messages.

When both GPS (1 and 2) are connected, it shows the number of satellite, 3D fix, but an error message Bad GPS signal health. When I chance the protocol from ERB to nmea, the message is gone, it still shows 3dfix but the plane starts to drift.

When I disconnect gps2, all error messages are gone.

But number of satellite is always 0

Please have a look at the screen pictures:


The M+ doesn’t output an accurate satcount, in my experience. It always shows zero satellites, even when it has a good fix. So the 0 satellites thing is normal, at least for the M+. If you’re seeing 0 satellites on both the M+ and your standalone GPS, that’s an issue, the standalone GPS1 should be giving a satcount.

OK. Thanks. I will report this issue to Emlid.