Black Box 3600 MODEM manual Pin Signal Descriptions, Dce

Installation

Table 2-1. Pin Signal Descriptions (Continued)

	EIA-	CCITT
Pin	232D	V.24	Signal	Description
7	AB	102	Signal	Signal or common signal and dc
			Ground	power ground. **
8	CF	109	Receive	A positive level from the modem
			d Line	indicating the presence of a
			Signal	received signal (carrier detect). *
			Detector
9	--		+12	+12 voltage reference
			Volts
10	--		-12 Volts	-12 voltage reference
11	--		Signal	This circuit indicates probability
			Quality	of errors in the received data: a
			Indicator	positive level indicates poor signal
				quality while a negative level
				indicates good signal quality. †
15	DB	114	Trans-	A transmit data rate clock output
			mit	for use by an external data source:
			Clock	Positive clock transitions
			(DCE)	correspond to data transitions.
17	DD	115	Receive	A receive data rate clock output
			Clock	for use by an external data sink:
				Positive clock transitions
				correspond to data transitions.
18	--	141	Local	A positive level causes the modem
			Loop-	to enter the local analog loopback
			back	test mode.*

** Modem options may force these signals on or cause them to be ignored.

*** Refer to Appendix C, Hardware Options.

*† This function can be disabled or its logic sense reversed by hardware straps.

Modem 3600 2-5