User guide

Chapter 1 – Product Description and Specification
10 Multi-Tech Systems, Inc. MultiModem Cell User Guide
9-Pin Fem-D Sub Serial Connector
The following table explains the pin functions.
DE9 Pin Assignment
Female Connector
DE9
Pins
RS232 Signals
DCE
RS422 Full
Duplex Signals
Signal
Direction
Pin 1
Data Carrier Detected (DCD)
RxD-
Out
Pin 2
RXD
RxD+
Out
Pin 3
TXD
TxD+
In
Pin 4
Data Terminal Ready (DTR)
TxD-
In
Pin 5
Ground
Ground
N/A
Pin 6
Data Set Ready (DSR)
Ready To Send -
(RTS-)
Out – RS232
In – RS422
Pin 7
Ready To Send (RTS)
Ready To Send +
(RTS+)
In
Pin 8
Clear To Send (CTS)
Clear To Send +
(CTS+)
Out
Pin 9
Ring Indicator (RI)
Clear To Send -
(CTS-)
Out
4-Position DIP Switch
Switch Position
Up/On
Down/Off
Description
Position 1
Off
DTR Reset Disabled
Position 1
On
DTR Reset Enabled
Positions 2-4
Only valid for serial builds
Position 2
Off
No TXD Termination
Position 2
On
TXD Diff Pair Terminated
Position 3
Off
No RTS Termination
Position 3
On
RTS Diff Pair Terminated
Position 4
Off
RS232 Mode
Position 4
On
RS422 Mode
Note: Positions 2 and 3 should only be used in RS422 Mode. Enabling TXD/RTS termination may be required to avoid
errors at high bit rates or long cable lengths. Multi-Tech Systems tested the cable up to 1,000 feet , but the
maximum may be more with termination enabled and lower data rates.
DIN Rail Mounting
Your modem can be mounted in a rack enclosure using the DIN Mounting kit supplied with your product.
Vertical Mounting
Perpendicular Mounting