StaRFIshrail System

Describes a complete StaRFIshrail system

Complete System

The Hub is the central component in the system.  Up to 32 RFID reader points can be connected to the hub, so there can be 32 points at which you can monitor the presence of your trains.  If you need more RFID points, then another hub can be added, and connected by CBUS to the first hub.  Up to 16 hubs can be connected this way, which would give a massive 512 RFID points.
Each hub requires a 10V-20V dc supply, with approximately 24 watts of power consumption.  This might seem a lot of power, but most of it is being used by the readers, and the whole system will run cool.
The hub is connected to your control computer system by Ethernet (preferred), or by CBus or USB serial.  DCC and LocoNet are too slow for the amount of data that can be generated, although bridging into these systems is possible - other hobbyists may want to do this.

Hub Connections

The hub board is just 100mm by 85mm, and contains the following connections:
1] 8 RJ45 (Ethernet-type) connectors, for connecting to the readers,  Each RJ45 can control 4 RFID points, and carries both data and power.
2] DC In. A 2.1mm/5.5mm barrel connector - any standard ac/dc power supply (Wall Wart) can be used, with a voltage of 10-20Vdc, and a power rating of 24W (2A at 12V, 1.5A at 18V).
3] USB - a micro USB connector, for connecting into a computer system, either for transferring data, or for programming.
4] Ethernet - 100M Ethernet, for transferring data to a computer, such as for JMRI.
5] CBUS - a port using CAN, for transferring data between hubs, and for sending data to other CBUS compatible modules, where there is no central control point.


The hub has 8 physical RJ45 reader ports, clearly marked on the hub pcb (printed circuit board).  Each of the RJ45 connectors carry both signals and power between the hub and the readers.  There is a limitation on the total length of each port cable, about 20 metres in total, due to capacitance in the cable.  Each RJ45 port can have up to 4 RFID points on it - no harm will be done if there are less than 4 RFID points on a port, or even no cable at all.
When using a combination of single and dual readers on a single cable, the use must make sure that there is no address overlap (see a more detailed description in Installation/Readers).
Readers are available in Single, Dual and Quad versions - Quad versions are the most cost effective.  Readers and aerial length must be matched for best performance.
Note that when a reader is powered up, ALL aerials must be connected, otherwise the reader chip will become hot, and failure could occur.


Each reader has an aerial attached - for a Single reader one aerial, for a Dual reader 2 aerials, and for a Quad reader 4 aerials.  The length of the aerial wire must be matched to the reader, and are available in short (13cm), medium(23cm) and long(43cm).  The aerials are placed at the RFID points where you want to monitor the trains.  The aerial is small, only 25mm by 15mm, and you can mount them under a 9mm (3/8") baseboard.  The RF field is also small, so you will not get false reads, even on N-gauge, where the tracks are spaced at 33mm.


StaRFIshrail tags are 6mm by 9mm, and have a read distance of 30mm.  They are very thin at 0.5mm. These are small enough even for N-gauge, but are used for all gauges up to O.
The picture shows a StaRFIshrail tag under a N-gauge 0-6-0 shunter.

Setting up the Hub

The Hub has an Address switch, and Option switch, a Program switch and a Reboot switch, as well as links and LEDs
Address Switch
The address switch is used for setting the hub address in a system where there are multiple hubs.  In a single hub system it should be set to 0.

Option Switch
This is used to set various options, including how the data is formatted, and to get into programming mode.  Set to 0 for first operations.

Program Switch
This switch is used in the same way as all MERG modules, for changing between SLim and FLim, and using FLim configuration. This works together with the LEDs "S" (green) and "F" (yellow).

Reboot Switch and Recovery Link
This is used only in programming.

There are LEDs to indicate status, both of power supplies, and activity ot various points.

Your computer control

The hub can connect to your computer control system by several methods.
This is the preferred method of connection, as it gives the widest bandwidth, and is most easily integated with JMRI and RocRail.  It has limited functionality, and responds only to those commands needed, and transmits data in only the formats required.  It can handle TCP (for JMRI and MERG FCU and RocRail), and UDP (for possible other systems).  The Ethernet IP address can be set up from command line programs.

This is a MERG compatible device, and can connect to a normal CBus for working in Slim or Flim mode.  The hub is a producer module only, although you can use the MERG FCU utility to set node number, and hence DDES number.  The CBus port is also the method to connect multiple hubs together, though in this case you should have a dedicated CBus network just for the hubs.

USB can be used in several ways.
1] For programming the board (both firmware and software) from a terminal program.
2] For interrogating and setting up the board from a terminal program.
3] For receiving data from the hub.

Plug and Play

The StaRFIshrail system is meant to be "Plug and Play".  Just powering up the hub, connecting a reader and an aerial and you can immediately detect RFID tags. 
For CBus users, the system from the box powers up in Slim mode, but you can change this to Flim mode in the normal way you would with other MERG modules.
For JMRI and RocRail users, the user will have to set the Ethernet address.  Note that the Hub will be delivered with an IP address of - which can be changed by you at any time.  If you want  us to set a different address, then you can email us immediately you have placed an order, and we will set the address for you.


One of the major causes of systems not working is the cabling - anywhere there is a connection, it can go wrong. Also, cabling needs to be predictable - it's all very well to define, say, a twisted pair as an interconnect standard, but the characteristics depend on may factors - conductor thickness, insulation thickness, twist distance to name a few.  And the actual connector can also cause a problem, who hasn't had a wire come out of a screw terminal, however careful you are when installing.
The cheapest consistent cabling was Ethernet Cat5 (or Cat5e).  So many of these cables are made that they are cheap, and easy to find.  Although StaRFIshrail only has 4 signals needed (clock,data,+ve and GND), and Cat5 has 8 wires in a cable, this meant that power signals could be doubled up, to reduce loss, and data and clock signals could use a twisted pair with GND, which gave a consistent characteristic.  The standard RJ45 connector is locking, so cables won't fall out even if mounted upside-down, and the cables are available in a variety of standard lengths, as well as different colours, which helps with installation.