Does a Garmin 430W need altitude encoder input?

[FORANE]

I just pulled an ARC RT-459A transponder and AK-350 altitude encoder which is gray code. This gray code from the altitude encoder was wired to the Garmin 430W.

I installed a Garmin GTX 327 transponder and used the RS232 encoder output of the GRT EFIS to feed the GTX 327.

Does the 430W need or benefit from running RS232 altitude encoder to the 430w?

[Carl Froehlich]

If memory serves - altitude input is required for IFR GPS approach. If you are using an ARINC connection between the 430W and your GRT EFIS, this input should already be provided via the ARINC - but you need to verify.

Note - if you are using the 430W as your ADS-B position out source, the 430W needs to be running with software version 5.0 or newer.

Carl

[RVDan]

The altitude encoder is used to assist the GPS initial acquisition time. It is optional, but preferred.

[FORANE]

Just what I needed to know.
Thanks guys

[Walt]

Don't know about the other stuff but this is From the 430W install manual:

"To take full advantage of the 400W Series unit capabilities, an optional barometric altitude source is recommended for automatic sequencing of fix-to-altitude (FA) and hold-to-altitude (HA) leg types.
If no barometric altitude data is provided to the 400W Series unit, FA and HA legs must be manually sequenced."

"Barometric altitude is not required by the 400W Series unit to meet the requirements of TSO C146a."