There are actually two distinct problems we're having with our 898c.
1) NMEA Output
NMEA output only works when powered by a automotive battery, NOT with our 14.8 Volt Lithium batteries. I can't fathom why this could be -- specs are 10-20V, and it's not like I'm using an inverter, and am worried about waveform... right? Any ideas why this is happening?
2) No GPS fix in SON files = can't export depths
Normally, I use NMEA output (see #1), but since that didn't work, I'm hoping to salvage the depth data by exporting it from the SON files.
On opening them, however, I noticed that they contain no GPS info at all. Zero's straight across the board. This in itself isn't a deal breaker, if I could only extract the depths at 5-second intervals from the SON files. I used HumViewer, and it looks like it's going to do it, but then the csv never gets created. I'm wondering if this is because it needs GPS / track info in order to export depths? I can see the depths are correct all the way through, so if I could just extract them somehow, this day of data collection could be recovered. (All we're really using is depths -- no imagery).
A note that I'm wondering if the lack of GPS in #2 is also due to the battery issue. Never had this problem before, when using car batteries. We're using high quality (and expensive) Lithium Ion batteries, so I'm having a hard time figuring out why this would be happening.
Thanks for any pointers, especially for #2! I'm dreading the thought of redoing that day's work :-(