Introduction; Eia/Tia 232-D (Modem To Computer) Interface - Motorola 326X V.34 User Manual

Introduction

This appendix describes the following:
Audio connector (DIAL LINE, LEASE/PRIVATE LINE, and PHONE) pinouts vary
by country. See Appendix C for your country's pinouts.

EIA/TIA 232-D (Modem to Computer) Interface

The modem's digital interface conforms to the EIA/TIA 232-D standard and ITU
V.24, ITU V.28, and ISO 2110; the modem should be connected to a data terminal
with a compatible digital interface (Table B-1). NOTE: For DTE rates greater than
38.4 kbps, refer to the "Cabling" section to determine cables and lengths.
Table B-1.
Modem/Computer Interface Connections
EIA/TIA
Pin 232-D ITU V.24
1 — —
2 BA 103
3 BB 104
4 CA 105
5 CB 106
6 CC 107
7 AB 102
8 CF 109
9 — —
10 — —
11 — —
B-2 Cabling and Interface Pinouts
• Interface pinouts common to all modem models, including:
— EIA/TIA 232-D, and ITU V.35 Recommendation modem-to-computer
interfaces
— NC IN and OUT network control port interfaces
• 326X/326X-SDC cabling requirements and diagnostics
Signal Definition
— Not used.
Transmitted Data Digital data transmitted from the local terminal to the remote modem.
(TXD)
Received Data Demodulated data received by the local terminal from the remote
(RXD) modem.
Request To Send Sent from local terminal to local modem to ready it for data
(RTS) transmission.
Clear To Send Passes from the local modem to the local terminal when the data port is
(CTS) clear to transmit data. Occurs in response to Request To Send.
Data Set Ready Indicates the local modem is ready to transmit and receive data.
(DSR)
Signal Ground Common signal. Provides a common ground reference point for
interface circuitry.
Data Carrier Passed from the local modem to the local DTE when an acceptable
Detect (DCD) carrier signal is received by the modem.
— Not Used.
— Not Used.
Answer/ Signal passed from terminal to modem to select answer/originate
status. When signal is on, answer signal is selected. When signal is off,
Originate Select
originate signal is selected. This signal works with Mode=External.