Changing CV values in NCE snap-it

[pugdogg55]

I recently got 2 NCE snap-it's to control 2 switches. I have successfully hooked them up and have them running with separate addresses from my NCE power cab. I wanted to change the CV value so that hitting 1 would toggle their direction rather than hitting 1 for one direction and 2 for the other direction.

 

I followed the directions to change the correct CV according to the snap it manuel (CV 548 I think, don't have it next to me right now) and I believe I do everything right, but it seems that the CV doesn't change. According to the manual I should

Hit prog/esc and hit 7 to get to the accessory programming page.

Type in the accessory address

Enter the CV number I want to change

Enter the value

Then hit enter and escape. 

 

For some reason it acts like the CV isn't changed at all (like its default value) Am I missing some step? It says I don't need to connect the shorting plug but do I? I haven't tried that yet. Any help would be appreciated. 

[BigDaddy]

This

makes it sound like you do need the shorting plug

[pugdogg55]

i just tried changing the CV with the shorting plug both in and out with the other snap-it disconnected and it still acts as though there's no change to the CV (the manuel sys to change CV548 to value 1 (default 0))

EDIT:

I re-reaad the instructions and looked at the wording a little more closely. I think to be able to toggle like I want I have to use wired in push buttons and am not able to do a toggle command from the NCE power cab. Can anyone confirm this?

[B. Bryce]

I suggest you contact Ed at NCE.  He is their expert on their electonic devices.  If it can be done via the Power Cab, he will know what to do.

[BigDaddy]

pugdogg55

I re-reaad the instructions and looked at the wording a little more closely. I think to be able to toggle like I want I have to use wired in push buttons and am not able to do a toggle command from the NCE power cab. Can anyone confirm this?

I read (in the link I posted above) that CV548 controls how the push buttons function. 

The duration of the output pulse and the capacitor re-charge time are both programmable by changing the appropriate CV value.   All well and good but one would think that a stationary decoder ought to be able to control the switch machine too and the buttons are an extra convenience or to allow other operators to work a turnout.

The instructions leave much to be desired.

[rrinker]

 The DCC command for stationary decoders has 2 states. Normal and Reverse, or CLosed and Throown, or whatever two words you want to use, or your system uses.

 I don't know of ANY that toggle fromt he throttle. You have to tell it to go one way or the other - and if you didn't, there's be no 'previous' value for the throttle to display the current position. Many do, however, allow either two pushbuttons or one pushbutton to be a toggle.

 Not sure why you'd want to use just one button to toggle on the throttle - as I sai, if the value never changed, each time you called up that address, you would have no way to know which way it currently is set. I know NCE stores this information and it's retrievable. Maybe not quite the same as Digitrax - if I call up the same stationary decoder on 4 different Digitrax throttles and hit Closed on one throttle, the other 3 will ALSO all change to show the current state of closed. Or if using say the DS64 stationary decoder with local buttons connected - it I either use a toggle button or individual buttons and set a particualr address to Thrown, all throttles (and JMRI if connected) will see this happen in real time. But even with a single button configured as a toggle, if yoou use a thrttole, you have to select the address and then push either closed or thrown to move the turnout, there's no way to make one buttoon be a toggle back and forth. Different DCC packets are sent to the decoder depending on which button you push. So it will always be like this.

 Switching from train running to turnout operating and then back to train running is ackward at best, regardless of the brand of DCC system, IMO. The only reasooon I would even control turnouts via DCC is to wire up a dispatcher panel for control, using something like JMRI. For turnouts controlled locally by the crew, buttons are much easier to use. Or toggle switches, or whatever type of input a particular stationary decoder can accept.

                                    --Randy