XpressNET cable

XpressNET™ cable

XpressNET™ cables use normal telephone wire, or twin core twisted pair wire for lengths over 100 m. (300 ft.), and come equipped with three flavors of plugs:

Plug

Employed by

DIN-5 180°

Lenz

Mini DIN-8

ZTC Controls

RJ-12, RJ-14 or RJ-25

Atlas
Hornby
Lenz
Roco

RJ-12, RJ-14 and RJ-25 are actually not connector types, but telephone interface standards that use the same modular plug with different wiring.
RJ-12	Uses all 6 available pins
RJ-14	Uses only the 4 central pins
RJ-25	Uses all 6 available pins

The XnTcp interface is equipped with a RJ-14 jack. If also your system uses RJ jacks, make sure to buy a straight-through connection cable with 4 (or 6) wires. In a straight-through cable the pins of one plug are connected with the same pins of the other plug (i.e. pin 1 with pin 1, pin 2 with pin 2, and so on). Be aware that most phone cords available on the market are crossover (rolled) cables (pin 1 of one plug connects with pin 6 of the other plug, pin 2 with pin 5, and so on). If you decide to build your own cable, be aware that a special crimping tool is required.

If your DCC system is equipped only with DIN-5 180° or Mini DIN-8 jacks, buy a RJ cable and replace one of the two plugs.

The following table reports the pins assignment of each type of plug.

XpressNET™ signals	A	B	C*	D*	L	M	Not used
Meaning	RS485 A	RS485 B	Control Bus	Control Bus	+12 Volts	Ground
RJ-12 pins	4	3	1	6	5	2
DIN-5 pins	5	4	-	-	3	1	2
miniDIN-8 pins	3	2	5	6	8	1	4 and 7

* C and D are not used by the XnTcp interface.

The above information was obtained from the XpressNET™ specifications (PDF file) and from the O Gauge in the Garden page by John Walker.

Alternatively, you can mount on the prototyping board a DIN-5 180° or Mini DIN-8 jack in lieu of (or in addition to) the RJ jack.

Jack	Supplier	Code	US$	Remarks
Din-5 180°	Digikey or others	CP-2350-ND	0.72	Right/Angle
miniDIN-8	Digikey or others	275-1045-ND	1.15	Right/Angle

When installing the above jacks:

Do not solder any pin to the round pads of the prototyping board, since they are connected to the PIC microprocessor;
Solder the pins of the shield to unused square pads (for retention purposes), but do not connect them to GND or any other signal.

The DIN-5 180° jack, owing to its size, cannot fit between the two cards and must be thus installed on the outer side of the prototyping board (i.e. opposite to the 20 pins connectors)

XpressNET™ is a trademark of Lenz Electronik, Gmbh