flickroll
Well Known Member
I am working on a panel upgrade that will have among other things an AFS 4500, G430W, GTX327 (or SL70), and the AFS ARINC adapter.
The G430 needs baro corrected altitude for RAIM prediction. The AFS instructions are not clear on how to do this.
I think you could do this one of 2 ways:
One method is to feed the AFS encoder RS232 TX to the 327 RS232 RX (this happens anyway - required for altitude info to the 327), then use the 327 RS232 TX to feed the G430, using Garmin 430 RS232 Channel #2 (#1 is used for fuel data straight from the AFS EFIS). A question: does the AFS unit send baro corrected altitude, or pressure altitude? I would think it sends pressure altitude since the 327 needs pressure altitude information.
Another method is to split the AFS encoder 232 TX to feed the 327 and the 430 separately. With this method you'd split the cable leaving the AFS unit into 2 wires, one going to the 327, the other to the 430, again to Garmin 430 232 port 2.
The drawback I see with method 1 is if your transponder goes belly up you will lose the altitude info to the 430. May be a rare event, but it is a possibility. Another drawback with method 1 is I don't think it would work with an SL70. It does not output Icarus altitude which is what the 430 is looking for.
I think method 2 is the preferred way to go, although I am not clear if AFS sends baro or pressure altitude...
In any event, for folks with AFS units and a 430, how did you accomplish this requirement? One of the 2 methods shown above, or something different?
Thanks
The G430 needs baro corrected altitude for RAIM prediction. The AFS instructions are not clear on how to do this.
I think you could do this one of 2 ways:
One method is to feed the AFS encoder RS232 TX to the 327 RS232 RX (this happens anyway - required for altitude info to the 327), then use the 327 RS232 TX to feed the G430, using Garmin 430 RS232 Channel #2 (#1 is used for fuel data straight from the AFS EFIS). A question: does the AFS unit send baro corrected altitude, or pressure altitude? I would think it sends pressure altitude since the 327 needs pressure altitude information.
Another method is to split the AFS encoder 232 TX to feed the 327 and the 430 separately. With this method you'd split the cable leaving the AFS unit into 2 wires, one going to the 327, the other to the 430, again to Garmin 430 232 port 2.
The drawback I see with method 1 is if your transponder goes belly up you will lose the altitude info to the 430. May be a rare event, but it is a possibility. Another drawback with method 1 is I don't think it would work with an SL70. It does not output Icarus altitude which is what the 430 is looking for.
I think method 2 is the preferred way to go, although I am not clear if AFS sends baro or pressure altitude...
In any event, for folks with AFS units and a 430, how did you accomplish this requirement? One of the 2 methods shown above, or something different?
Thanks
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