Motorola 326X V.34 ユーザーズマニュアル

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Cabling and Interface Pinouts B-5
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Pinouts
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.
2
Transmit Data (A)
Digital data transmitted from the local terminal to the remote 
modem.
3
Receive Data (A)
Demodulated data received by the local terminal from the 
remote modem.
4
Request To Send 
(RTS)
Sent from local terminal to local modem to ready it for data 
transmission.
5
Clear  To  Send 
(CTS)
Passes from the local modem to the local terminal when the data 
port is clear to transmit data. Occurs in response to RTS.
6
Data Set Ready 
(DSR)
Indicates the local modem is ready to transmit and receive data.
7
Signal Ground
Common signal. Provides a common ground reference point for 
interface circuitry.
8
Data Carrier 
Detect (DCD)
Passed from the local modem to the local DTE when an 
acceptable carrier signal is received by the modem.
9
Not  Used.
10
Not Used.
11
Not Used.
12
Receive Clock (B)
Timing signal extracted from the received carrier. Local modem 
transmits this signal to the DTE to synchronize received data.
13
Transmit Clock 
(B)
Local modem sends an internally generated transmit timing 
signal to the local terminal to synchronize transmitted data.
14
Transmit Data (B)
Digital data transmitted from the local terminal to the remote 
modem.
15
Transmit Clock 
(A)
Local modem sends an internally generated transmit timing 
signal to the local terminal to synchronize transmitted data.
16
Receive Data (B)
Demodulated data received by the local terminal from the 
remote modem.
17
Receive 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 
Ready (DTR)
108.1—Sent by the DTE, this signal causes connection of the 
modem to the phone line.
108.2—Sent by the DTE, this signal allows connection of the 
modem to the phone line.