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Taking Control- Team Digital SMD84 Decoders & NCE Powercab



<p>Hello again! This layout is nearing its seventh birthday, which came as quite a shock to me when I realised. With that in mind I am now determined to get it to a point where I can run trains. I made a crash list of jobs that needed doing, top of the list was to finally sort out the control system and point wiring.I had despaired of ever getting any of this working in a coherent way and it was one of the many reasons the layout ended up in transport boxes in my workshop. Having toyed with numerous methods I bit the bullet this year and decided to use an NCE Mini Panel and decoders to control the Seep solenoids. Having trawled around for decoders that were both "affordable" and powerful enough to switch solenoids, I saw a seller on Ebay with several Team Digital SMD84's at very reasonable price. These looked ideal, especially since they do 8 points per board, meaning I would only need two. They had an onboard CDU and were serial bus compatible to boot.Having finally built the control box- see my layout topic, I got my head around the wiring and installed the decoders. Amazingly they worked when I called up the default address through the track bus from the handset! This led to needing to program all the macros in for route setting, which meant changing the output address' on the SMD84, the instructions of which appeared to be in "Greek."Finally to the point of this entry- how to change the address' using NCE Powercab and the "Smart Program" feature of the SMD84.

  • Make sure you have the updated manual- early ones have a misprint. The corrected one can be found here-
  • I opted to set ONLY the one decoder up at a time, so track power/DCC was carrying the signals, not the serial bus. I did this by hooking the decoder up direct to the power cab.
  • Smart Program on the SMD 84 uses ACCESSORY COMMANDS instead of the program track or other direct method of CV setting.
  • For NCE systems read any "c" in the SMD instructions table as 2 on the handset and "t" as 1.
  • The LEDS on the board are set up so they flash at different stages of the smart program. To change the output address from default (1-8) you push the "Smart Button" until the red led pictured starts to flash, then let go.

blogentry-9516-0-04385100-1494164205_thumb.jpgThe smart button is the small push button in the centre of the frame at the edge of the board.

  • You are now set up in "smart mode" ready to set the output numbers. I wanted the points on my first board to be numbered 101-108, so I pushed "select accessory" on the power cab and set the first number. The screen should look like this.


  • When you have the right number, push enter, the screen will then give you the option of sending the command. If you want STALL MOTORS to be addressed then push "1" if you want SOLENOIDS, push "2."


  • Once the command 1 or 2 is sent the SMD84 automatically remembers the eight outputs from the starting number, this worked fine for me.

​What to do if it goes wrong?

  • Pushing and holding the Smart button on the SMD 84 for about 18 seconds or until both the LEDS in my first picture flash ALTERNATELY will reset the board to factory defaults when you let go the Smart button.

Setting CV 29 Value

  • I did this through Ops mode programming for an accessory decoder, off the NCE screen. See their manual, I only had the one decoder connected, a good idea IMO. You can change the accessory decoder address to enable ops mode programming via the DCC bus, but my brain was hurting enough for one day.
  • Recommended value of CV 29 for an NCE system is 24 which will allow you to control the SMD84 via the DCC/track power ysing NCE macros. See note about the serial bus below.
  • The SMD84 WILL NOT change CV 29's value until reset, I switched it off then on again but you can set CV 7 to a value of 0 to do that.
  • You can tell if CV29 is wrong or any other mistake has been made because it starts doing its own thing. See note above!

So thats how to do that. I realise this is a fairly dry blog entry but I couldn't find a step by step for it, so I made one.I must thank Nigel Cliffe for his invaluable help and superior knowledge.


EDIT- I have contacted Team Digital to find out if their command bus is NCE compatible, they have confirmed it is NOT NCE COMPATIBLE, so you must use the SMD84 off the track power/DCC. This is less of a problem in smaller scales and on little layouts as due to the individual firing of the solenoids and the onboard CDU the current used is fairly minimal. Team Digital advise the use of their "DCC Booster" if you have sound locos etc and want more power- http://www.teamdigital1.com/prod_catalogue/dccboost_product/dccboost.html


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