3Com 5124M-TPCL manual Table A-7 -Pin Cable Pinouts and Port Assignments

Table A-7. 50-Pin Cable Pinouts and Port Assignments

Hub	Hub	Hub	Transceiver		Hub	Hub	Hub	Transceiver
		Function/	Function				Function	Func-tion
Port#	Pin#				Port#	Pin#
		Polarity	/Polarity				/Polarity	/Polarity
Port 1	26	RX, +	TX, + (1)		Port 7	38	RX, +	TX, + (1)
Port 1	1	RX, -	TX, -	(2)	Port 7	13	RX, -	TX, - (2)
Port 1	27	TX, +	RX, + (3)		Port 7	39	TX, +	RX, + (3)
Port 1	2	TX, -	RX, -	(6)	Port 7	14	TX, -	RX, - (6)
Port 2	28	RX, +	TX, +	(1)	Port 8	40	RX, +	TX, + (1)
Port 2	3	RX, -	TX, -	(2)	Port 8	15	RX, -	TX, - (2)
Port 2	29	TX, +	RX, +	(3)	Port 8	41	TX, +	RX, + (3)
Port 2	4	TX, -	RX, -	(6)	Port 8	16	TX, -	RX, - (6)
Port 3	30	RX, +	TX, +	(1)	Port 9	42	RX, +	TX, + (1)
Port 3	5	RX, -	TX, -	(2)	Port 9	17	RX, -	TX, - (2)
Port 3	31	TX, +	RX, +	(3)	Port 9	43	TX, +	RX, + (3)
Port 3	6	TX, -	RX, -	(6)	Port 9	18	TX, -	RX, - (6)
Port 4	32	RX, +	TX, +	(1)	Port	44	RX, +	TX, + (1)
					10
Port 4	7	RX, -	TX, -	(2)	Port	19	RX, -	TX, - (2)
					10
Port 4	33	TX, +	RX, +	(3)	Port	45	TX, +	RX, + (3)
					10
Port 4	8	TX, -	RX, -	(6)	Port	20	TX, -	RX, - (6)
					10

A - 10 ONline Ethernet 24-Port 10BASE-T Module Installation Guide