Piko 35013 switch decoder with Roco Z21

My garden layout was always supposed to be fully DCC controlled. After putting money into my digital setup and the locomotives (here and here), the next step was enabling the handling for rail-track switches. Luckily the product needed for that is easily available and is not even extremely expensive considering its functionality.

Piko 35013 is a switch decoder dedicated for G-scale usage. It offers 4 independent and programmable outputs. Moreover each output can serve two switches at once, so with some clever design one could control up to 8 switches using one device. This may be more than many of us have on our layouts, including myself. And that means I had an option to go full digital for just 70 Euro.

The product comes in a standard Piko box. The content includes the device itself and a detailed manual. The decoder is secured inside the package with a properly shaped piece of a cardboard. Everything arrived unscathed.

The manual covers all important topics and is bilingual including German and English descriptions. Everything is explained very clearly with pictures and wiring diagrams.

There are some points in the manual worth mentioning:

• The declared minimum input voltage for the device is 12V. This means the product could be potentially used also for smaller scales. That's some interesting news and it makes it a reasonable alternative for the Digitrax DS64 decoders that I'm using on my N-scale layout.
• Piko claims the outputs are short protected. That's really great and it turns the decoder into an even more interesting option for replacing Digitrax. DS64's outputs are not protected at all and that forced me to send the units for repair twice already.
• The decoder offers different modes for operating the outputs. It can drive 2-wire and 3-wire switches, as well as LEDs and light bulbs. This all looks very promising (and again - seems like much more than the functionality of Digitrax).

The decoder itself is just a small black box.

Upon opening the cover, we gain access to its terminals. Those include: one input, four outputs and a programming jumper.

The PCB seems to be covered with some sort of a lacquer. This is probably the way the device is made weather resistant. Looks very solid!

First tests with Roco Multimaus and LEDs connected to the outputs. LEDs are blinking and everything seems to work just fine...

An important point to remember here is the different numbering scheme used by Piko and Roco. There's a +4 shift in digital switch addresses. So in order to use Piko switch #1, we need to target address #5 on the Roco Multimaus controller.

The next tests involved Roco z21 station with mobile application control. Again - everything behaved correctly... And again, the already mentioned address shift is in effect forcing me to adjust addresses on the z21 application.

I have tested 3 configurations in total:

• Roco Multimaus -> Roco 10764 station -> Piko 35013 decoder -> 2 x Piko 35271 switches

• Z21 Mobile App -> Roco z21 -> Piko 35013 decoder -> 2 x Piko 35271 switches

• Z21 Mobile App -> Roco z21 -> Uhlenbrock Power 8 booster -> Piko 35013 decoder -> 2 x Piko 35271 switches

In all those configurations my setup worked correctly for basic operations. I was very afraid of adding the booster to the chain but it did not have any bad effects. The switches could still be controlled easily and it worked just great!

And that's when I've decided to try something more. I needed only 3 out of the 4 available outputs for the switches on my layout and I thought it would be a good idea to use the last one for something else. Traffic lights were my preferred choice. After all the decoder had the "LED constant output" mode and it should be usable for choosing red and green signals.

I tried it... and it did not work. I've had huge problems programming the decoder using Roco z21. The station could neither write or read the CVs properly. I've even used the z21 Maintenance desktop application and it seemed to work but the "LED mode" was still not enabled. I've spent three afternoons trying different ideas but it was all for nothing...

Here's a video documenting the initial success and the later failure.

 

I've contacted both Piko and Roco to get some insight on possible cause of the incompatibility. Unfortunately at the time of writing this post, the issue is still not solved. I suspect Roco z21 is simply not able to program the decoder. And I also suspect that if I used a different station to change the relevant CVs, I would later be able to operate the "LED mode" from z21.

The summary is: Roco z21 can be used to operate Piko 35013 but it cannot be used to program any new behavior.

Alright, but the basic switching still works perfectly fine. I've installed the electric mechanisms (Piko 35271) on my layout with all the wiring...

...connected it to the decoder...

...and hid the device under one of the buildings to add some weather protection.

It all works. My switches can be operated remotely now. The layout is fully DCC enabled. Success? Yes, but I somehow still wish I could add the traffic lights, too...