When I program a locomotive, why does my power cab say cannot read CVS?What can I do about this and why does it show that?I have N scale
froggy,
You are getting this message when your Power Cab is trying to read the decoder's manufacturer and ID numbers - i.e. just before programming in the short and long addresses? What locomotive and decoder are you trying to program?
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I have seen this with Katos and the decoder is a MRC.
Is this a sound MRC decoder, by chance? The Power Cab was given extra "oomph" in programming track mode to handle the heavier current draw from sound decoders. I have heard of programming problems with MRC decoders - sound or non-sound versions.
Yes, the locos have sound.I have not heard very good about MRC decoders. How are ya saupposed to program one with sound?
Froggy,
MRC sound decoders are problem-matic - I have an Athearn MP15AC with factory installed MRC DCC/Sound - It was impossible to program the decoder on 3 different Digitrax systems(even with the programming booster). I was finally able to program it 'on the main' by calculating the loco address in 'hex', then writing that to CV17 & CV18, then setting CV28 to '36'. To top it off, the MRC decoders do not do CV 'read-back' - so you cannot 'see' what may be already written to the CV. I will never buy another MRC decoder equipped engine(maybe that is why Athearn has dropped MRC and now uses Soundtraxx Tsunami sound decoders).
There are several conversion calculator on the web, Here is one:
http://www.2mm.org.uk/articles/cv29%20calculator.htm
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Most times when your Power Cab says can't read CV's, indicates that the decoder is not getting power.
It is true with some MRC decoders they will not read back CV's, But I have seen the display read 255 and you have to program in blind faith- just enter the numbers you want and move on.
Does the loco make any sounds- lights come on ??
Like Randy, I have not gone out an purchased any more MRC decoders (I have one). Until I see some better reports I will not get any more.
MRC 1600 series N scale sound decoders do not support CV readback. (I think they used all the available memory to have 30 different horns and bells).
I ' ve heard that the newer 1800 series do have readback but since I won't buy any more of them, can't say for sure.
Basically, you program the old fashioned way. Keep plugging values into the CV until it responds the way you want. Keeping a record of what's been tried already helps.
Martin Myers
Thanks for all the replies. I have heard so many bad things about MRC decoders. In fact I've sent two back to MRC for a refund.