DPM-100 Digital Panel Meter Modbus
®
Display
Instruction Manual
16
Power Connections
Power connections are made to a two-terminal
connector labeled POWER on the back of the scanner.
The scanner will operate regardless of DC polarity
connection. The + and - symbols are only a suggested
wiring convention.
Figure 11. Power Connections
Serial Communications
Connection
Serial communications connection is made to an
RJ45 connector labeled M-LINK on the back of the
scanner. The Modbus Scanner uses the PDA1485
RS-485 adapter to interface with other Modbus
devices and the PDA8485 RS-485 to USB converter
to connect to a PC. The same port is used for
interfacing with all expansion modules (
e.g.
external
relays, digital I/O).
Figure 12. Serial Communications Connections
Serial Communications
Connections Table
The table below shows the terminal connections for
3-wire RS-485 devices.
PD6088
Master
PD6088
Snooper
PC
Connection
Modbus
Slave
Meter
Modbus
Level
Gauge
On-Board
Terminals
On-Board
Terminals
PDA8485
RS-485 to
USB
RS-485
RS-485
G
GND
DO
DI
DO
DI
DO
DI
D-
A (-)
DO
DI
DO
DI
DO
DI
D+
B (+)
Three Wire Connections
In order to wire the 5 pins for use as a 3-wire half-
duplex RS-485 connection, it is necessary to create a
jumper connection between DI – DO and DI- – DO- as
shown below.
Figure 13. Three-Wire RS-485 Connection
F4 Digital Input Connections
A digital input, F4, is standard on the scanner. This
digital input connected with a normally open contact
across F4 and COM, or with an active low signal
applied to F4. It can be used for remote operation of
front-panel buttons, to acknowledge/reset relays, or to
reset max/min values. See
of capabilities.
Figure 14. F4 Digital Input Connections
AC or DC
POWER
Required External Fuse:
5 A max, 250 V Slow Blow
POWER
+ -
