Inc Sound Module Decoder - Manual

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8.2.1 Simple 3 Step Speed Table

Start voltage, Max Voltage and Mid-point voltage can be used to set up a

simple three step speed table. In most cases, a simple 3 step speed table is the

easiest way to set up the throttle response curve you want. For higher resolu-

tion in your throttle response curve, you can use a loadable speed table.

You can set up a simple 3 step throttle response curve by setting V-start

(CV02), V-mid (CV06) and V-max (CV05). This method requires program-

ming just 3 CVs. Once these three CVs are set, you are ready to run the loco,

no programming of CV29 is needed for this type of speed table.

8.2.2 V-Start: CV02

Start voltage, V-start, is the extra voltage added to the motor drive voltage at

the first speed step. This adjustment allows you to compensate for the locomo-

tive motor’s efficiency. The range you can program for this CV value is from

000 to 255. Each value increment represents an increase of approximately 1/2%

of the total motor drive voltage, when a “straight-line” throttle response curve

is used. The value of 255 represents 100% motor voltage. Digitrax Series 3,

4, 5 & 6 decoders use V-start in 128 speed step mode and run loadable speed

tables in 128 speed step mode. Most earlier version Digitrax decoders disregard

V-start in 128 speed step mode and run loadable speed tables in 14 or 28 speed

step mode.

8.2.3 V-Max: CV05

Setting CV05, V-max or maximum voltage, specifies an exact voltage that is

applied to the motor at the highest speed step Setting V-max to a lower value

than 255 allows you to limit the top speed of a locomotive. The range of avail-

able V-max CV values is 000 to 255. A value of 128 applies 50% of total volt-

age to the motor at the highest speed step. A value of 255 applies 100% voltage

at the highest speed step.

For backward compatibility, CV05 values of 000, 001 & 255 all mean 100%

voltage at step 28. If V-Max is accidentally set below V-mid, the decoder will

use the V-mid setting as V-max.

V-max is not available when loadable speed tables are in use. In this case, set

the maximum voltage by programming speed step 28 as the max voltage.

8.2.4 V-Mid: CV06

Setting CV06, V-mid or mid point voltage specifies an exact voltage that is

applied to the motor at speed step 15 (or speed step 7 in a 14 step system). The

range of available V-mid CV values is from 000 to 255. A value of 128 applies

50% of the total voltage to the motor at step 15 (28 step system). A value of

255 applies 100% voltage at the middle speed step.