Questions Regarding Garmin 18x LVC Connection and PPS Signal

Hardware
,
1

Dear Ouster Support Team,

I hope this message finds you well.

I am currently using the Velodyne VLS-128 and recently purchased a Garmin 18x LVC from Amazon to obtain timestamp data.

To verify its operation, I connected the GPS to the interface box and modified the settings via the Web UI. However, the PPS status remains “Absent” and does not change.

(The issue I had with accessing the Web UI has been resolved thanks to your support. I truly appreciate the assistance provided by your team.)

Upon reviewing the user manual, I noticed that when the Garmin 18x LVC is purchased directly from Velodyne, it arrives pre-configured for use.

I would appreciate your guidance on the following points:

  1. Is it not possible to use a Garmin 18x LVC purchased from a third-party vendor (i.e., not from Ouster/Velodyne)?

  2. If it is compatible, would configuring it according to “Figure 7-6 Garmin 18x LVC Configuration” in the following manual allow it to function properly? https://data.ouster.io/downloads/velodyne/user-manual/alpha-prime-rev4-user-manual.pdf

Thank you very much for your time and support. I look forward to your response.

Best regards,

2

You will need to reprogram the Garmin to set it to the Chapter 7 values for baud rate, PPS timing, NMEA sentence, etc. The program, SNSRXCFG, which runs on Windows is available at the following link: Garmin: GPS18x OEM Software Update Collection .

You will need a RS232 port to connect to the 18LVC. The following USB to RS232 device should work (or anything similar):

You will need to set the baud rate on the adapter to match the default value and then make the change the 9600 baud.

3

Thank you for your response!
I will purchase the adapter you suggested and try connecting it.

4

Hi Karin,

I had a similar problem, I would appreciate if you could update if this solution worked for you,

5

The issue has been successfully resolved.

After purchasing the USB Serial Adapter recommended by jlg, I modified the GPS harness according to “Figure 1: Computer Serial Port Interconnection” on page 10 of the technical manual.
Technical manual：https://static.garmin.com/pumac/GPS_18x_Tech_Specs.pdf

Then, using the SNSRXCFG software, I configured the settings as described in “Figure 7-6: Garmin 18x LVC Configuration” from the manual. As a result, I was able to confirm that the connection was successful, as the PPS indicator at the bottom of the Web UI showed “Locked.”

Thank you very much for your support.