Overview and comparison of past assignments s88 to RJ45

Overview of past assignments
	Vendor / Standard
Pin RJ45	s88-N	digital-bahn.de	opendcc.de	railway-lauf.de	iek.de
1	+12V/+5V	+12V	GND	DATA	DATA
2	DATA	DATA	CLK	GND	DATA
3	GND	GND	GND	GND	GND
4	CLK	CLK	PS	CLK	CLK
5	GND	GND	GND	PS	PS
6	PS	PS	RESET	RESET	RESET
7	RESET	+12V	+5V	+5V	+5V
8	RAILDATA	RAILDATA	DATA	+5V	+5V

Following comments on these pin-outs:

The assignments of railway lauf.de and iek.de are electrically unfavorable, because the sensitive lines are not paired with static lines. Both assignment were obviously driven by the wish of having a simple pcb layout. To make things worse, the assignment of IEK does not strengthen the GND.
A possible higher supply voltage of 12V and an appropriate shift of the threshold for the signals offers more margin, so that disturbances cannot affect the signal lines. Therefore also the 12V supply was allowed as an alternative to the 5V supply. The user must pay attention that only if all attached modules are tolerant to the higher supply than 12V may be turned on by the command station or by a s88 booster. Else the 12V supply may cause damage to the decoder.
In the assignment of digital bahn.de the RESET line was omitted, which may cause compatibility problems. The RESET line is contained in s88-N.
The optimal GND assignment of opendcc was weakened in favour of RAILDATA (i.e. the track signal).
To avoid uncontrolled GND-loops or loss of secure isolation, the cable shield should be left open.
To avoid the cable colour for s88-N patch cables should be blue.