User Manual

Programming MRC Sound Decoders on the Main Using Hexadecimal

conversions for CV Numbers 17 and 18

Due to low programming track power in certain DCC systems, programming sound decoders on

the program track may not be possible, especially when assigning the decoder a four (4) digit

address. This programming procedure must be performed on the mainline, where more power is

available for programming sound decoders.

If your DCC system allows simple 4-digit address programming on the main (OPS Mode

Programming) then simply input the 4-digit address and press ENTER.

A second step might be needed for certain sound decoders, which would be activating the 4-digit

address by changing the value of CV#29. Inputting a value of 34 (constant) tells the decoder to

use the 4-digit address.

Some DCC systems need to have CV#s 17 and 18 programmed separately to assign the

decoder a 4-digit address.

You cannot simply split the four digit address in 2 halves and

input these into CV#s 17 and 18. A conversion from decimal numbers to hexadecimal

numbers is required. Once the hexadecimal conversion for the 4-digit address is performed,

this number is then separated and then each section entered into its respective CV#s 17 and 18.

To perform this operation you need a scientific calculator or the calculator accessory on your

computer. Make sure your computer. calculator is set for the scientific mode.

Using the “constant” number of 49152, add your 4-digit address to this number.

Example For example let’s say your 4-digit address is 1998.

1.Add 1998 to 49152, which equals 51150, [1998+49152=51150].

2.Change the setting on your calculator to HEX and enter 51150. You will get a hexadecimal

number of C7CE, [51150 decimal equals C7CE hex].

3.Separate this value into two sections, C7 and CE. .These become the hex numbers for CV#s

17 and 18 respectively. However, before entering these values into the CVs, you have to convert

these hex values into decimal values.

4.Enter C7 into the calculator under the Hex mode, then switch the calculator’s setting back to

decimal. You will get 199. C7 [hex] =199 [decimal]. Enter 199 into CV#17.

5.Enter CE into the calculator under the Hex mode, then switch the calculator’s setting back to

decimal. You will get 206. CE [hex] =206 [decimal]. Enter 206 into CV#18.

This gives the decoder a 4-digit address of 1998

The next step is to go to CV#29 and input the “constant” number of 34 [decimal].

This number tells the decoder to use the 4-digit address along with analog disable, 28/128 speed

steps, and normal direction, [locomotive forward]. There are other constant values that you can

enter into CV#29 to change the decoder’s parameters. Please refer to your decoder’s instruction

manual or to ourCV#29 Table which can be found on our website under “Prodigy Info Page”,

[www.modelrectifier.com].