bakerstu
commented
4 years ago Gil has provided this opinion multiple times.
To date, I don't recall receiving this concern from any manufacturer having first hand experience with the Next18(-S) connector "standard". In fact, I have overwhelming heard from manufacturers that it is easy to provide protections and that they have not observed any issues in the field in the form of damaged product or customer complaints in nearly 10 years of service.
TN-9.1.1.5, provides no less than three different suggestions on how the required protections can be implemented. As indicated in the S-9.1.1.5 references (Informative) section, it is intended to be in harmony with RCN-118 and NEM 662.
The statement about about there being no mandatory protection facilities is untrue. The standard does indeed require protections starting at line 92: "The system board of the vehicle, as well as the decoder, must be designed so that if they make different use of LS_A/AUX5 and LS_B/AUX6, no damage to the vehicle system board or decoder will occur."
This issue will not be fixed and no changes to the document will be made.
This feedback comes from Gil Fuchs:
My understanding is that this is a direct translation of RCN-118. I do not see this as a good candidate for a standard since there is an inherent direct incompatibility between the Next18 and Next18-S in the definition of pins 7 and 16, in table 3.2 page 7. There are no mandatory protection facilities included in this standard, and since the same connector is used in both versions (sound and non-sound) this could lead to user errors and reports of damaged equipment, resulting at reputational damage to NMRA.