Quick Question - What are "NEM" Pockets on Model Railway Stock?

NEM stands for Normal European Modelling, and the NEM Standards were developed to allow for greater standardisation and interoperability in the hobby. NEM couplings must conform to the NEM 360 standard (available in French, here) and specify the height, size, and functioning of the coupling.

The NEM Pocket standard is NEM 362 (again, in French, here) and defines the stadard for interchangeable NEM couplings. The standards are closely monitored by the US NMRA, which means that manufacturers such as Kadee can provide the market with advanced automatic (un)couplers that are NEM compliant.

NEM pockets ensure that all railway stock is compatible. Hornby (except Railroad), Bachmann, and most others adhere to these standards for HO and OO rolling stock and locomotives. There are similar standards for other scales and gauges.

The list of most common standards is as follows:

• NEM 351 - Coupling standards, terms, and general introduction;
• NEM 355 - N gauge coupling pockets standard;
• NEM 358 - TT gauge (TT scale) coupling pockets standard;
• NEM 360 - HO coupling standard;
• NEM 362 - HO coupling pockets standard;
• NEM 363 - HO replacement coupling pockets standard;
• NEM 365 - standard for O gauge coupling.

The organisation in charge of the information (MOROP) is always looking for volunteers to help translate these documents into English.

How to Set Train Address with Piko Digi Fern

The Piko Digi Fern is the name given to the remote control device that comes with the Piko Digital starter set (for example Piko 57156). Out of the box you usually get some rails, a DCC locomotive (set to C, or 003, more on that later) some rolling stock, the Digi Fern remote, and an IR receiver.

The first step is setup - and it's important when setting train addresses with the Piko Digi Fern that everything is set up correctly. There are two ways to set the address:

• on the main layout;
• on a service track.

If you intend to program "on the main", you must be certain that you know what you are doing, as the programming signal will be sent to every DCC device that is linked to the IR receiver! For this reason, I usually program on a service track - the procedure is the same.

Special note for those programming on the main layout line - please disconnect all accessories (such as DCC Cobalt switch engines or similar) and LED lights before continuing. I have lost a few LEDs due to this oversight, as well as reprogrammed a couple of accessories!

(My service track is just a bit of G231 (Piko H0 55201 H0) and a bit of G239 (Piko H0 55200 H0 Straight track G239) nailed to a board, with a couple of banana connectors to hook up the IR receiver!)

Setting the Train Address with the Piko Digi Fern

The special key to start programming is usually the third from the left on the top row, next to the red "stop" button.It looks like a double-branch or double point. There's a similar single point one next to it, used to activate DCC accessories like points and switches.

I'll call this key [P] for now. The key sequence is:

• [P][P][train address][P]

So, if [P][P]123[P] is typed, all locos on the track will get address 123. In fact, any number from 001 to 127 can be used, but the Piko Digi Fern is only really capable of handling 12 locos at once, and the IR receiver and power supply seem to peter out at around the 4th loco (depending on other accessories power draw and track length.)

During the process of setting the address, the loco will move, in twitches, so it's best to start with it  as far back on the service track as possible.

Once programming has finished (and the light on the IR receiver has stopped flashing), the train can be selected using the train button, followed by the loco address. When the system is switched on, the A - D keys are allocated to loco addresses 1 - 4, so it is easiest to stick with these numbers, as just the 'channel select' button A to D can be used to pick up control of a loco.

The official Piko Digital User Guide has now been translated into English, and can be downloaded from the Piko Web Site.

Any questions or comments can be left below in the comments section. Links are affiliate links that go to Amazon.co.uk, for which the author receives a modest commission for any products bought.