Black Box LR5100A-T manual RS232 Null-Modem Cable Configuration, Figure D-9 RS232 Null-Modem Cable

Interface Pinouts

RS232 Null-Modem Cable Configuration

DB25 MALE					DB25 MALE
	1	Shield	Shield	1
	2	Transmitted Data	Received Data	3
	3	Received Data	Transmitted Data	2
	4	Request To Send	Data Set Ready	6
	6	Data Set Ready	Request To Send	4
	20	DTE Ready	Received Line Signal Detector (CD)	8
	7	Signal Ground	Signal Ground	7
	8	Received Line Signal Detector (CD)	DTE Ready	20
15		Transmit Timing DCE Source	Receiver Timing DCE Source 17
17		Receiver Timing DCE Source	Transmit Timing DCE Source	15

24Transmit Timing DTE Source

Transmit Timing DTE Source 24

Figure D-9 RS232 Null-Modem Cable

The connecting cable must be a shielded 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.

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