Motorola 326X V.34 manual ITU Rate V.35 Modem-to-Computer Interface Pinouts, Pin Signal Definition

ITU Rate V.35 Modem-to-Computer Interface Pinouts

The modem’s digital interface conforms to ITU Rate V.35. The modem should be connected to a data terminal with a compatible digital interface (see Table B-1).

Table B-2.

ITU V.35 Modem/Computer Interface Connections

Pin	V.35 Signal	Definition
1	Frame Ground	Frame (or protective) ground.

2Transmit Data (A) Digital data transmitted from the local terminal to the remote modem.

3Receive Data (A) Demodulated data received by the local terminal from the remote modem.

4	Request To Send	Sent from local terminal to local modem to ready it for data
	(RTS)	transmission.
5	Clear To Send	Passes from the local modem to the local terminal when the data
	(CTS)	port is clear to transmit data. Occurs in response to RTS.
6	Data Set Ready	Indicates the local modem is ready to transmit and receive data.
	(DSR)
7	Signal Ground	Common signal. Provides a common ground reference point for
		interface circuitry.
8	Data Carrier	Passed from the local modem to the local DTE when an
	Detect (DCD)	acceptable carrier signal is received by the modem.
9	—	Not Used.
10	—	Not Used.
11	—	Not Used.

12Receive Clock (B) Timing signal extracted from the received carrier. Local modem transmits this signal to the DTE to synchronize received data.

13 Transmit Clock	Local modem sends an internally generated transmit timing
(B)	signal to the local terminal to synchronize transmitted data.

14Transmit Data (B) Digital data transmitted from the local terminal to the remote modem.

15 Transmit Clock	Local modem sends an internally generated transmit timing
(A)	signal to the local terminal to synchronize transmitted data.

16Receive Data (B) Demodulated data received by the local terminal from the remote modem.

17Receive Clock (A) Timing signal extracted from the received carrier. Local modem transmits this signal to the DTE to synchronize received data.

18	Loop 3 Control	Initiated at the local terminal and passed to local modem,
		causing it to initiate a local analog loopback test.
19	—	Not Used.
20	Data Terminal	108.1—Sent by the DTE, this signal causes connection of the
	Ready (DTR)	modem to the phone line.
		108.2—Sent by the DTE, this signal allows connection of the
		modem to the phone line.

Pinouts Interface

Cabling and Interface Pinouts B-5