I am getting 0-degree glitches at least once a day following the recent WD updates (see previous reply).
I caught another glitch while recording the VP2 traffic using a separate PC, again tapping off the RS232 wire transmitted by the VP2 console to WD. After a few painful hours of processing the data I found this:
2017/11/12.17:13:23
06 | ACK (COMMAND)
4C 4F 4F 3C 00 86 09 23 75 B4 02 32 B3 01 0F 07 | LOOP
42 01 FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF 4E FF FF FF FF FF FF FF 00 00 00 00 00 2B 00
11 B5 07 00 87 00 62 0B 23 00 20 00 2E 02 FF FF
FF FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 33 03 06 4B CC 02 59 06 0A
0D 80 50
4C 4F 4F 3C 00 86 09 23 75 B4 02 32 B3 01 0F 07 | LOOP
42 01 FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF 4E FF FF FF FF FF FF FF 00 00 00 00 00 2B 00
11 B5 07 00 87 00 62 0B 23 00 20 00 2E 02 FF FF
FF FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 33 03 06 4B CC 02 59 06 0A
0D 80 50
4C 4F 4F 3C 00 86 09 23 75 B4 02 32 B3 01 0F 07 | LOOP
42 01 FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF 4E FF FF FF FF FF FF FF 00 00 00 00 00 | Loop halt
2017/11/12.17:13:24
2B 00 | LOOP continue
11 B5 07 00 87 00 62 0B 23 00 20 00 2E 02 FF FF
FF FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 33 03 06 4B CC 02 59 06 0A
0D 80 50
Look above where I have annotated the LOOP halt/continue. The VP2 console is stalling the transmission of a LOOP packet for approx 1…2-seconds compared with a normal transmission, note the date/time stamp is tagged by the capture software I am using. This effect is exactly the same when I captured the data from a previous glitch (see reply #8 in this thread). Another point to note is that the stalled LOOP packet has exactly the same content including CRC as the previous LOOP packet giving a clear indication that the VP2 console processor clearly paused the RS232 transmission, probably while processing a higher priority interrupt - I am guessing saving data in EEPROM due to the duration.
My VP2 console (#6312) is an older hardware revision (pre April 2006) with firmware v1.90 with a native RS232 data logger i.e. no USB.
Brian: any thoughts as this looks to be a WD issue handling the VP2 data port when LOOP packet transmission is paused mid-flight? I may contact Davis technical support and find out what the pause duration could be if that helps.