Yesterday I was asked to install an older Trimble 122 on a 2002 C-IH 2388.
This combine was equipped with the Touch Screen Yield Monitor that came with the combine. The previous owner had not used GPS.
On other C-IH combines, I have found the 5 pole Metri-Pak connector for GPS under the access door to the right of the Cab. I did not find the connector at this location. Upon consulting the owners manual, I noticed a drawing indicating that this connector was inside the cab on this combine.
I searched under the gearshift compartment and found the connector complete with dustcap. I used an Adapter made to fit the 5 pole connector to power and DB9. This allows us to use the standard 122 Data cable to mate to the combine.
This all went fairly well and we pulled the combine out of the shop to check for operation. The two LEDs lit and blinked on the 122 indicating that power was present. After a while the LEDs quit blinking and stayed lit which should indicate lockon for both GPS and Beacon correction.
I then started playing with the AFS display. I am not familiar with it at all but I have experience with the Ag Leader products. I found a screen to tell the system that GPS was present. I was then looking for a screen that displayed Lat/Lon as "proof" that my install was successful. I could not find such a screen.
I was also confused by the Status indicator on the right side of the normal operating screen. If I unplugged the GPS, I got a message indicating loss of GPS which would be appropriate. I then powered down the GPS by unplugging it and cleared the error screen on the AFS display. I then returned to a normal operating screen of the AFS display When I powered up the GPS again, I got a flashing GPS indicator on the right side of the display above the word CARD. After the GPS reacquired position as indicated by its LEDs, the flashing GPS indicator went away.
This confused me as I thought the flashing GPS indicator would go to a solid black indication showing that GPS was good. Is appears that "no news is good news". In other words, since the system did not report loss of GPS or poor GPS indicated by the flashing GPS block that the GPS is good?
Apparently the word REC will be shown in black when actually harvesting. We did not simulate this but I guess we could have by running the separator, lowering the head and driving forward.
Is there any other way to check that GPS is good such as an information screen?
Apparently these monitors do not allow for GPS speed but always use WHEELS or possibly radar. I had the 122 configured for 4800 8N1 with GGA and VTG ON. These are the settings that I would expect for an Ag Leader. It appears that only the GGA message is needed. I assume that also having the VTG ON will not cause a problem. Is this correct??