CV29 Calculator
Description
CV29 packs six independent decoder settings into a single number, one bit each — direction, where FL is controlled from, DC/analog conversion, RailCom, which speed table is active, and short vs. extended addressing. Working out which decimal value to program (or figuring out what an existing CV29 reading actually means) by hand means converting binary to decimal in your head, which is exactly the kind of fiddly, error-prone step this calculator exists to remove.
Check the boxes for the options you want and the CV29 value updates automatically. It works the other way too — type a CV29 value you've read off a decoder into the number field, and the checkboxes update to show exactly what it means.
Sources
Bit assignments are reproduced directly from NMRA Standard S-9.2.2, "Configuration Variables For Digital Command Control, All Scales" (July 2012), Configuration Variable 29 ("Configurations Supported") — the authoritative definition, not a secondhand summary.
Disclaimer: this covers CV29 for multifunction (locomotive) decoders only. Bit 7 is the Accessory Decoder flag — a value with bit 7 set belongs to a different CV29 bit layout for accessory decoders (defined in the same standard at CV541, optionally CV29), not the one this calculator decodes. Bit 6 is reserved by the NMRA and should stay 0; if your decoder's manual documents different behavior for a bit, trust the manual over this calculator — some manufacturers add non-standard uses for otherwise-reserved CVs.