Perle Systems IOLINK-520 manual Null-Modem Cable Configuration, 12 V.35 Null-Modem Cable

Link Interfaces Reference

V.35 Null-Modem Cable Configuration

DB25 MALE							DB25 MALE
	1	Protective GND			Protective GND	1
	9	Transmitted Data (A)			Received Data (A) 11
	10	Transmitted Data (B)			Received Data (B) 12
	11	Received Data (A)			Transmitted Data (A)	9
	12	Received Data (B)			Transmitted Data (B) 10
	18	Transmitter Signal Element Timing (A)		Receiver Signal Element Timing (A) 14
	19	Transmitter Signal Element Timing (B)		Receiver Signal Element Timing (B) 16
	14	Receiver Signal Element Timing (A)		Transmitter Signal Element Timing (A) 23
	16	Receiver Signal Element Timing (B)		Transmitter Signal Element Timing (B) 25
	23	Transmitter Signal Element Timing (A)		Transmitter Signal Element Timing (A) 18
	25	Transmitter Signal Element Timing (B)		Transmitter Signal Element Timing (B) 19
	20	Data Terminal Ready	Data Channel Received Line Signal Detector (CD)			8
	8	Data Channel Received Line Signal Detector (CD)			Data Terminal Ready 20
	7	Signal Ground			Signal Ground	7
	4	Request to Send			Data Set Ready	6
	6	Data Set Ready			Request to Send	4

Figure 3 - 12 V.35 Null-Modem Cable

The connecting cable must be a shielded cable.

Circuits which are paired (contain an (A) and (B) reference) should be connected to twisted pairs within the connecting cable.

This cable is needed when it is necessary to connect two units back-to-back and a set of modems is not available. Note that this cable specifies DB25 connectors on each end to allow direct connection to the link interface connector on each unit.

The link speed must be defined for each of the two units.

3.10— IOLINK-PRO & 520 Reference Manual