KB935: CV49-CV56 - FX Special Effects

This article was last updated on May 18, 2012, 5:21 p.m. | Print Article | Leave Feedback

Decoders with FX function features have 4 user configurable, independent special effects generators.

All current production Digitrax Decoders use FX3 functions so this article is not applicapable to these decoders.


CAUTION: Decoders with FX3 function generators use different CVs to control the decoder outputs. All current production Digitrax decoders use FX3 function CVs. Before using these CVs to program your decoders make sure that they are FX and not FX3 decoders.

The Real FX effects are set up by programming CV values as described below.

F1/F2 NOTE: If using DH142, DN142, DN141K2, DN149K2 series decoder, when F1 is set up for FX, F2 must also be set up as FX (It can't be used as standard on/off function.) If you want to use a combination of FX & standard on/off functions, please use F1 as the standard on/off function and F2 as the FX function.

Setting Up FX Effects On Function Outputs


1. Each function lead has an FX control CV associated with it. Using Table IVa below, determine which CV you need to program to set up an FX feature for the function lead you are working with. For example, if you want to set up an FX feature on your forward headlight, you will use CV49 to control the FX feature for the lamp attached to the white wire on your decoder.

Some decoders do not have function wires attached. See the specific decoder instructions to determine which "pad" on the decoder is for each function. Use thin wire or wire saved during previous decoder installations to solder function wires to the pads associated with the function you want to use.

FX generators are controlled by CVs 49 to 56:


FX Control CV #

Function #

Lead Color

CV49

F0/Light Forward

White

CV50

F0/Light Reverse,

Yellow

CV51

F1 Function 1

Green

CV52

F2 Function 2

Violet

CV53

F3 Function 3

Brown

CV54

F4 Function 4

White/Yellow

CV55

F5 Function 5

White/Green

CV56

F6 Function 6

White/Blue



Note: Decoders with FX3 function generators use different CVs to control the decoder outputs

2. Each FX effect has a CV value that generates the FX effect you want and controls how the effect works with respect to locomotive direction and the head light (F0) function.

The FX CV value is made up of 2 digits. The second digit determines which FX effect will be generated. The first digit determines how the effect will work with respect to the locomotive direction, the head light and other functions. Use table below to determine the second digit and Table IVc to determine the first digit of the FX CV value to program into the CV selected in step 1.

The second digit of the FX CV value determines which type of FX effect will be generated.

Second Digit CV:

FX CV value second digit (HEX)

Type of FX effect generated

x0

No effect, normal function control of lead

x1

Random flicker

x2

Mars light

x3

Flashing head light

x4

Single pulse strobe

x5

Double pulse strobe

x6

Rotary beacon simulation

x7

Gyralite

x8

Rule 17 dimmable headlight, dim when F4 is active or locomotive direction is opposite normal direction of travel (NDOT)

x9

FRED or "end of train" light

xA

Right ditch light on when loco is running forward and F0 is on. When F2 is on, the right ditch light flashes alternately with the left ditch light to simulate ditch light operation at a grade crossing.

xB

Left ditch light. on when loco is running forward and F0 is on. When F2 is on, the left ditch light flashes alternately with the right ditch light to simulate ditch light operation at a grade crossing.

xC-xF

Digitrax reserved for effects expansion.



The first digit of the FX CV value determines how the effect generated will behave. For example, two strobe lights can be set up to flash alternately by setting one to phase A and the other to phase B. The strobes can also be set up to be on when the loco is moving forward and off when moving backward.

How FX effect generated will work:

FX CV value

first digit (HEX)

How the FX effect generated will work

0x

Forward direction, ON with function ON, effect phase A

1x

Reverse direction, ON with function ON, effect phase B

2x*

Non directional effect, ON with function ON, effect phase A

3x*

Non directional effect , ON with function ON, effect phase B

4x*

Forward direction, ON with F0 ON & function ON, effect phase A

5x*

Reverse direction, ON with F0 ON & function ON, effect phase B

6x

Special Logic for Fwd Ditch Light or Rule 17 dimming

7x

Special Logic for Rev Ditch Light or Rule 17 dimming

8x-Fx

Digitrax reserved for future FX expansion.


Reversing Headlight Note: For decoders with part numbers that end in 2 (DH142, DN142, DN149K2, etc.) these work with F0-Forward (White) & F0 Reverse (Yellow), only if CV61 is set to a value other than 00 to map the yellow lead to F4.

3. Program the FX CV value from step 2 to the FX CV identified in step 1.

If you are using the PR1 Computer programmer, a special FX set up section is available where you can just "point and click" to set up the effects you want to use. The software lets you select which function lead and which FX feature you want from a menu so you don' have to use the tables above to determine which CV or CV value to use.

4. You can repeat steps 1, 2 and 3 to set up a total of 4 FX effects on any 4 function leads you choose. If you want any function lead to remain a simple on/off lead, leave it programmed to the factory default of CV value 00.

If your decoder has more than 4 function leads, you can set up only 4 FX effects and the other function leads will be simply on/off functions.

Customizing FX Effects-FX Rate and Keep Alive: (CV62)


CV62 lets you control the rate and keep-alive brightness for each FX effect you set up. The CV value for CV62 is made up of 2 digits, the first digit and the second digit.

The first digit controls the keep alive/baseline off voltage for incandescent lamps. This value should be between 0 and F. A value of 0 gives no keep alive and a value of F gives maximum keep alive. Values between the high and low allow you to vary whether the lamp actually goes off between light pulses or whether it stays on very dimly or more brightly. (If you are using LEDs, the first digit for CV62 should be 0.)

The second digit controls the rate of the FX effects programmed. This value should be between 0 and F. A value of 0 gives a fast rate and a value of F gives a slow rate of operation. We recommend you start with a 4 and adjust it up or down until you get the effect you are looking for.

Ditch Light Hold Over Time (CV63)


If you are using the ditch light effect in conjunction with F2, CV63 lets you set up a hold over time to control how long the ditch lights continue to blink after F2 turned off by releasing the key on the throttle. Remember that F2 is a momentary key on most Digitrax throttles that will keep function 2 on as long as you hold the key down and then turn function 2 off when you release the key. This allows the ditch lights to be on steady during regular operation and to begin alternate flashing when F2 (usually the horn) is activated and to continue flashing alternately for a predetermined length of time after F2 is released; just like the prototype. A value of 00 yields no hold over time, a value of 40 yields a realistic time of about 5 seconds. A value of 255 (xFF hex) yields about 20 seconds hold over time.


FX Examples

Any function lead on the decoder can be set up for any FX effect by programming its associated FX CV to the appropriate FX CV value. For example, if CV53, the FX CV for F3, is programmed with an FX CV value of 02, the brown F3 function lead will be a Mars light when F3 is turned on for this decoder address and the decoder's direction is forward.

FX CV EXAMPLES


CVs that affect all FX function leads

Meaning

Recommended

CV# & CV Value

hex/dec

Effect on Decoder

Analog Functions Enable/Disable

13:xcF/207

All functionsF0 though F4 are ON in analog (DC) mode

Configuration Register

29:x06/006

Advanced 28/128 speed step mode, analog mode conversionenabled

Keep Alive/Rate

62:xc4/196

High keep-alive for lamps, Rate 4 for approx. 1 sec FXeffect rate

Ditch Light Hold Over Time

63:x40/064

5 Sec Ditch light holdover after F2 is turned OFF



CVs that affect specific FX outputs:

Function/

Color

CV # & CV Value

hex/dec

FX Effect Generated

F0 Fwd

White

49:x68/104

Rule 17 dimmable headlight,directional

F0 Rev

Yellow

50:x00/000

Normal directional reverse headlight, NO effect used

F1

Green

51:x6A/106

Right Ditch light, directional.F0 & F2 must be ON for this tooperate.

F2

Violet

52:x6b/107

Left Ditch Light, directional.F0 & F1 must be ON for this tooperate.

F3

Brown

53:x22/034

MARS light, ON when F3 isON(If we used {53:x32/050} we wouldget opposite phase MARS light)



To set up two alternating double pulse strobes on the green and violet function leads controlled by turning on both F1and F2, program CV51 to a CV value of x25/037 and program CV52 to a CV value of x35/053. This is an example of using the alternate effects phases A & B.

If you set up more than 4 effects to the output leads, the effects selected after effect 4 will be the same as the 4th effect selected, assuming the first effect was set up on CV49, the second on CV50, the third on CV51 and the fourth on CV52. An FX CV Value of 00 will set up the function lead as a standard on/off function lead with no FX effects generated.


Troubleshooting FX effects

Common problems with FX set up are:

Trying to program a decoder for FX when the decoder does not support FX. Be sure the decoder you are installing has FX features. Digitrax introduced FX in the summer of 1995 so if your decoder was made before then it does not have FX capability. Since 1995 all Digitrax premium decoders have included FX. Digitrax standard and economy decoders do not have FX features.

FX effects don't work as expected:

Review the qualifiers you set up for the effect. For example, if the effect is set up to come on only when F1 and F0 are active and the loco is headed in the forward direction, be sure you have met those conditions.

F1/F2 NOTE: If using DH142, DN142, DN141K2, DN149K2 series decoder, when F1 is set up for FX, F2 must also be set up as FX (It can't be used as standard on/off function.) If you want to use a combination of FX & standard on/off functions, please use F1 as the standard on/off function and F2 as the FX function.

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