Multi-Tech Systems 7500 - Manual (Page 127)

ION 7500 / ION 7600 User’s Guide RS-232 Connections
Chapter 5 - Features and Applications Page 127
RS-232 Connections
Refer to the “Hardware Reference” chapter for the ION 7500 and ION 7600 meters’
RS-232 specifications.
An RS-232 connection is made at the male DB9 connector (COM1) at the back of
the meter. The meter acts as a DTE device in all RS-232 connections. Use a null
modem cable for connecting a meter to a workstation or use a standard straight-
through RS-232 cable for connecting to an external modem. In either case, one end
of the cable must be equipped with DB9 female connector for mating with the DB9
male connector on the meter. The maximum cable length is 50 feet (15.2 m).
Computer Connections
Meter Connections
External Modem Connections
RS-232
50 feet (15.2
m) max
Null modem
DB9 female
connector to
COM1
RS-232
RS-485 loop
50 feet (15.2
m) max RS-232 to RS-485
Converter
DB9 female
connector to
COM1
50 feet (15.2
m) max
RS-232
DB9 female
connector to
COM1
Telephone network connection
between workstation modem
and remote modem
Remote modem