Configure a Trimble or Case IH receiver

Trimble and Case IH receivers can feed Ditch Assist® as long as their NMEA output is on and set the way Ditch Assist needs it: GGA and VTG at 5 or 10 Hz, 38,400 baud, everything else off (see What your receiver must send).

Where you set that depends on the system. Find yours below. Most of these can only be set from the tractor display, so do it on the tractor.

Before you start

Time: about 10 minutes, at the tractor.

• The receiver connected to its display, and powered up
• The right Ditch Assist GPS cable: the breakout cable for your receiver, or the generic DB9 GPS cable for a NAV II or NAV III harness (DB9 is a 9-pin plug, the same shape as an old computer serial plug)
• RTK corrections set up on the receiver the way Trimble or Case IH describes

Which system do you have? NAV II or NAV III controller (Precision-IQ display) · Autopilot with a Pro 700 or IntelliView 4 display · Trimble 372 receiver (RDI or Ag Remote)

Trimble with a NAV II or NAV III controller (Precision-IQ display)

1. Connect the DB9 cables

   Plug the Ditch Assist generic DB9 GPS cable into the DB9 serial cable on the Nav controller harness. The GPS cable has to run into the cab to reach it.

2. Open GNSS settings

   On the Precision-IQ display, go into GNSS settings.

3. Open the NMEA Messaging tab

4. Turn messaging on

5. Set the message rate to 5 Hz or 10 Hz

6. Pick Autopilot as the output port

Autopilot with a Pro 700 or IntelliView 4 display

1. Open Nav Settings

2. Tap Edit under NMEA Output Setup

3. Turn NMEA output on

4. Check the baud rate is 38,400

   The speed settings on this screen don't matter for Ditch Assist: leave them off.

5. Set Precision to 8

6. Set Accuracy to 8

7. Go back to the settings menu

8. Open NMEA Message Settings

9. Turn GGA on, at 5 Hz or 10 Hz

10. Turn VTG on, at 5 Hz or 10 Hz

    Leave every other message off.

Trimble 372 receiver (RDI or Ag Remote)

The easiest way is the RDI screen on a Pro 700 display, or the Ag Remote screen on Trimble displays. Both show a copy of the receiver's own small display, with arrow keys under it. You move around by tapping those arrow keys on the screen.

You usually set up Port A or Port C, because Port B normally connects to the RTK radio. Your setup may differ: use a port that isn't already in use.

1. Press the right arrow until you reach Configuration

   Usually twice.

2. Press the down arrow

   That opens the Configuration menu.

3. Scroll to the port you're setting up

   Port A or Port C.

4. Set the position output to NMEA

   It probably says TSIP now: Trimble's own format, which the control module can't read.

5. Set the baud rate to 38.4k

   The line now reads 8N1 NMEA 38.4k, as in the drawing.

6. Scroll down to NMEA1

   Each message name shows in capitals when it's on and in lower case when it's off.

7. Set GGA on, and every other message off

   GGA in capitals; all the others in lower case.

8. Scroll down to NMEA2

9. Set VTG on, and every other message off

   VTG in capitals; all the others in lower case.

10. Set NMEA OUT to ASAP

    ASAP means the fastest rate the receiver supports, typically 5 Hz.

Then check it

1. Plug the receiver into the Ditch Assist GPS cable

2. Switch the control module on and watch Status 2

   It should blink. That shows data is arriving, though how fast it blinks doesn't tell you the rate; the GPS badge in the next step shows the settings are right (see Read the Status 2 light). On DIG, check GPS State in the DIG web interface instead.

3. Connect the tablet and check the GPS badge

   It should show a fix with a satellite count, and a green RTK once the receiver has its RTK fix.

If it doesn't work

• Status 2 not blinking: nothing is arriving. NMEA not on, wrong port, or the DB9 transmit and receive lines swapped (Tx/Rx). Status 2 not blinking.
• Status 2 blinks, but the app has no GPS: baud rate not 38,400, or GGA and VTG not on. Status 2 blinks, but no GPS.
• Status 2 blinks in bursts with pauses: data is arriving unevenly; the cable and output work. Turn everything but GGA and VTG off.
• Blade slow to react or overshooting: check the message rate in the receiver's settings. It must be 5 or 10 Hz. The Status 2 light can't show you the rate.
• Nothing on a NAV II or NAV III setup: check the port isn't TM-200 Port A.
• The fix never reaches RTK: Stuck on Float.
• No GPS in the app at all: No GPS in the app.