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GRT WS Horizon and Garmin 430W Communication Problems

Pilotjim77

Well Known Member
I have the following equipment in my panel:
• Two GRT Horizon WS display units
• GRT EIS
• Garmin 430W
• Garmin 327 XPDR
• Garmin G5

I am having a connection problem between my 430W and Horizon WS. I'm receiving the following messages on the Horizon WS display unit:
"No GPS Data from serial 5"
"Serial Port 5: No Communication"

This problem occurred recently when I tried to figure out why I was not getting any data from the GPS to the autopilot. The autopilot was working only in the backup gyro mode. The 430 was talking to the display units just fine. The EFIS was displaying flight plan info, CDI, glideslope, and test page data from the 430. It was suggested that I change the RS 232 output on the 430 from MapMX to Aviation, so I did that. This did not solve the autopilot problem, but after I made this change, the above error messages began appearing on the WS display units. Changing the RS 232 output back to the original (MapMX) did not solve the problem. Right now, I continue to receive the above error messages.

I did check the autopilot configuration and found that the baud rate was set to 4800 instead of 9600, which was probably the cause of the original problem. However, I don't know how to correct the problem of the GRT WS displays not receiving any serial 5 inputs.

Any help on this problem would be appreciated. I have photos of all the configuration page entries for the 430W and both display units if that is helpful.

Jim
 
What autopilot? Is it 2 axis?
In order to have the autopilot track an ILS or LPV glide slope you will need to have the ARINC pairs hooked up. Usually these lines are switched through a DPDT switch so you can select direct control of the autopilot via the 430, or a 430 to EFIS to autopilot routing. This stuff is on the GRT Hx web page, HS should be the same. For other stuff you'll use the RS232 lines. I *think* (going from memory) I used aviation format out of the Garmin, into the EFIS. Check formats and baud rates, they all (430, GRT, autopilot) have to match. Look on the EFIS set up page for port 5. If the counter is running then it's getting data in.
 
What autopilot? Is it 2 axis?
In order to have the autopilot track an ILS or LPV glide slope you will need to have the ARINC pairs hooked up. Usually these lines are switched through a DPDT switch so you can select direct control of the autopilot via the 430, or a 430 to EFIS to autopilot routing. This stuff is on the GRT Hx web page, HS should be the same. For other stuff you'll use the RS232 lines. I *think* (going from memory) I used aviation format out of the Garmin, into the EFIS. Check formats and baud rates, they all (430, GRT, autopilot) have to match. Look on the EFIS set up page for port 5. If the counter is running then it's getting data in.

Forgot to mention the autopilot; it's a Trutrak ADI Pilot II.

The counter was running before I messed with the 430 configuration page. But now it is not. The EFIS is giving the "Serial 5: No Communication" message.

I have the aviation format setting now out of the Garmin on the RS232 page, but no joy. I changed it back to the "MapMX" but still no joy.
 
Check the wiring is intact?

I will be pulling the connectors next to check for any problems with pins, continuity, etc. I was hoping to find the problem without having to get behind the panel. I find it unlikely to be wiring since it was working fine a short time ago. But I guess anything's possible.
 
The wiring from the 430W to the WS EFIS was fine. It turned out to be a configuration setting in the 430W. The RS232 config page had aviation output on channel 1, and it needed to be on channel 3 according to the Garmin manual.

This corrected the "Serial Port 5: No Communication" issue. However, I'm still not getting gps signal from the EFIS to the autopilot. Tomorrow, I'll check the continuity from the WS EFIS to the autopilot.
 
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