Serial Communication Converters & Adapters Instruction Manual
32
Connections
To power the PDA7485, connect 12 VDC to the +12VDC and ground to
the GND screw terminals from the supplied 115 VAC/12 VDC adapter.
The PDA7485 may be configured for either a four-wire or two-wire net-
work. Figure 16 details the wiring connections from the PDA7485 to an
RS-422/485 serial device in a four-wire network.
Figure 16. Connections for PDA7485 in a Four-Wire Network
Figure 17 details the wiring connections from the PDA7485 to an
RS-422/485 serial device in a two-wire network when the DIP switches on
the PDA7485 have been set to the “2-Wire Mode”.
Figure 17. Connections for PDA7485 in a Two-Wire Network
The PDA7485 internally connects the /DI to the /DO and the DI to the DO
when the DIP switches are set to “2-Wire Mode”. Either the /DI or /DO
could be used to connect to /DATA and either the DI or DO could be used
to connect to DATA.
Two PDA7485 RS-232 to RS-422/485 Serial Converters could be used
as a serial extender to allow RS-232 serial devices to communicate over
long distances. This would allow an RS-232 device to operate up to
3,937’ (1,200 m).
PDA7485 to RS-422/485 Serial Device Four-Wire Connections
PDA7485 Serial Converter
RS-422/485 Serial Device
DO
DI
DO
DI
DI
DO
DI
DO
PDA7485 to RS-422/485 Serial Device Two-Wire Connections
PDA7485 Serial Converter
RS-422/485 Serial Device
DO
DATA
DO
DATA
