Basic Programing
Tsunami2 Electric User’s Guide
23
Setting the 3-Point Speed Curve
By default, track voltage is distributed to the decoder with no variation in a straight line and the
decoder responds instantly to the throttle setting. You can designate the amount of voltage
applied at the first, middle, and last speed step with CV 2 (Vstart), CV 5 (Vhigh), and CV 6
(Vmid) to compensate for track power or throttle control inefficiencies. First, set bit 4 (STE) of
CV 29 to 0. Then enter values from 1 to 255 into CVs 2, 5, and 6 to set the 3-point speed curve.
Each value is equivalent to roughly 0.5% of the total supply voltage. Use the calculations below
to determine starting, mid-point, and maximum voltage settings:
Vstart, Vmid, Vhigh = Supply Voltage × CV Value ÷ 255
Note
:
Use CV 218 (Analog Mode Motor Start Voltage) to set the starting voltage level for analog
mode operation. Refer to “Configuring for Analog Mode Operation” for more information.
If your system supports Operations Mode, refer to the steps below for an alternative method of
setting the 3-point speed curve:
1. Place the unit on the mainline and set the throttle to speed-step 1, and then increase the
value of CV 2 until the model responds to your preferred starting voltage.
2. Set the throttle to a medium speed step, and then increase the value of CV 6 until the
model responds to your preferred mid-speed voltage.
3. Set the throttle to the maximum speed step, and then increase the value of CV 5 until
the model responds according to your preferred high-speed voltage level.
Use the 3-Point Speed Curve
The figure shown below gives an example of how CVs 2, 5, and 6 can be used to change
voltage levels during operation.