ISO 11783 Task Controller works, but GS3 ignores NMEA 2000 GNSS PGNs

[DuduKramer]

Hello,

I have a question regarding the John Deere GS3 display and its support for NMEA 2000 GNSS data.

I have developed a CAN-based device that can transmit arbitrary CAN frames, including both ISO 11783 Task Controller messages and NMEA 2000 PGNs.

I have successfully implemented the ISO 11783 Task Controller protocol and have been able to send a DDOP to the GS3. The display recognizes the implement correctly, which indicates that my device is communicating properly over the CAN bus and that the GS3 is operating as an ISO 11783 Task Controller.

From what I understand, ISO 11783 references NMEA 2000 (IEC 61162-3) for GNSS information, so I expected the display to also accept standard NMEA 2000 GPS PGNs.

However, when I transmit the standard GNSS-related NMEA 2000 PGNs (such as 129025, 129026, 129029, etc.), the GS3 does not recognize my device as a valid GPS source and does not use the transmitted coordinates.

My questions are:

• Does the John Deere GS3 actually accept GPS position data from a generic NMEA 2000 GNSS device?
• Or does it only accept GPS information from John Deere receivers or through a proprietary protocol?
• If generic NMEA 2000 GNSS devices are supported, are there additional requirements besides transmitting the standard GNSS PGNs? For example, specific NAME fields, Address Claim configuration, Product Information, additional PGNs, certification requirements, or a particular initialization sequence?

Since the GS3 already accepts my ISO 11783 Task Controller implementation and DDOP, I am trying to understand why the NMEA 2000 GNSS portion is not being accepted.

Any information, implementation details, or CAN logs from a working GNSS receiver connected to a GS3 would be greatly appreciated.

Thank you!