3com 520 User Manual
B-6
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C
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WAN Port Connecting Cable – V.24/V.28
Support
The WAN port terminates with a 25-way D-type
female connector. The port can be configured to
support V.24 or V.28 signalling characteristics at data
transfer rates up to 19.2 Kbps. The WAN port
connecting cable is not supplied with the unit. The
following signalling characteristics should be
observed when purchasing or fabricating a suitable
cable.
Pin
Links
3Com end
pin no.
(25-way male
D-type
connector)
Signal name
Client end
pin no.
(25-way male
D-type
connector)
2
Transmit Data (TXD 103)
2
3
Receive Data (RXD 104)
3
4
Request To Send (RTS 105)
4
5
Clear To Send (RTS 106)
5
6
Data Set Ready (DSR 107)
6
7
Signal Ground (102)
7
8
Data Carrier Detect (DCD
109)
8
11
Signal Ground (AutoSense)
12
Signal Ground (AutoSense)
15
Transmit Clock (TXCLK
114)
15
17
Receive Clock (RXCLK 115)
17
18
Analog Loop Test (141)
18
20
Data Terminal Ready (DTR
108)
20
21
Remote Digital Loop Test
(140)
21
22
Ring Indicator (RI 125)
22
24
External Clock (EXCLK)
If clock signals are required, connect Pin 24 to Pins 15 &
17 at the 3Com end only.
Pin
Links
3Com end
pin no.
(25-way male
D-type
connector)
Signal name
Client end
pin no.
(25-way male
D-type
connector)
Rc.bk : RCAPPB.FRM Page 6 Thursday, July 10, 1997 9:53 AM