Asynchronous/synchronous modem & x21bis (db25, Female to db25 male) – Perle Systems RIO 5500036-17 User Manual
Page 187

RIO Remote I/O System User Guide
Installing a Long Distance Module (LDM)
Page 187
Chapter 2 Installing hardware and software
Asynchronous/Synchronous Modem & X21bis (DB25 female to DB25 male)
Note
Any connector pins not listed in the next table must not be connected.
DB25 female (LDU)
DB25 male (Modem)
Pin
Signal
Description
Pin
Signal
Description
2
TXD
Transmit Data
2
TXD
Transmit Data
3
RXD
Receive Data
3
RXD
Receive Data
4
RTS
Request To Send
4
RTS
Request To Send
5
CTS
Clear To Send
5
CTS
Clear To Send
7
GND
Ground
7
GND
Ground
8
DCD
Data Carrier Detect
8
DCD
Data Carrier Detect
15
TXC
Transmit Clock
15
TXC
Transmit Clock
17
RXC
Receive Clock
17
RXC
Receive Clock
20
DTR
Data Terminal Ready
20
DTR
Data Terminal Ready
Leased line
Modem at
host card
site
Modem
at
remote
site
DB25 female to male
adaptor.
DB25 female to male
adaptor.
DB25 female flying lead
to remote site LDU
DB25 female flying lead
from host card site LDU