Decoders on a noisy two-wire path with firmware 5.10 and below
Important Note
This does not happen with all decoders that are running on older firmware. The problem is related to a specific install location and setting and does not indicate a generalized problem with decoders running on firmware version 5.10 or below.
Issue
A decoder is installed, programmed and tests OK upon installation. The controller is programmed. When the system gets up and running, the decoder loses programming and fails. This can sometimes happen days or weeks later.
Why does this happen?
This can happen if a decoder is installed on a noisy two-wire path. Some decoders with firmware version 5.10 and below will fail.
What is a noisy path?
A noisy path is a simple way of saying that there are too many decoders trying to talk at one time on the same path. Sometimes too much resistance (due to a nick or cut on the wire path) can cause too much noise. Another cause could be that the wire path is too long or that incorrect wire was used during the install. Decoders with updated firmware have the capacity to recognize this error.
What is the fix?
The fix is to replace the decoder with one that has the current firmware. When the customer installs a new decoder, even if the decoder gets installed back onto the same noisy path, it should not fail.
You can advise the customer to throw away the old decoder; no need for an RMA on this as the decoder will still be under warranty.
How to check the firmware that the decoder is running on to verify replacement:
If the decoder has a serial number in the range between hf00080 – hf00180 then it will have the version 5.09 firmware and may be susceptible to this programming malfunction.