Rockwell Automation 2711 MODBUS COMMUNICATIONS FOR PANELVIEW TERMINALS - Manual (Page 6)

Publication 2711-6.9 - March 2000
6 Modbus Communications for PanelView Terminals
Making Modbus
Connections The PanelView Modbus protocol communicates with other devices
over an RS-232 (point-to-point) or RS-485/RS-422 (multi-drop) serial
link. Refer to the following pinout information to connect the
PanelView to a Modbus network.
Important: Follow the Modbus network layout and design as
specified by the user manual for your programmable controller.
Line Termination
The device at each end of an RS-485/422 network should be
terminated. A termination switch is provided on the PanelView (see
figure above). Enabling line termination provides an RC line
termination of .01mF and 120
Ω
. Do not use line termination for RS-232
communications. Do not terminate devices between the network
ends.
ATTENTION
!
Use a nonconducting probe to change the line
termination switch. Do not use a graphite pencil or
other conductive material. Failure to use a
nonconducting tool, may result in damage to the
PanelView.
PanelView
Refer to next page for a
description of pinout connections.
OFF = termination is off
ON = line terminated
Line Termination
DIP Switch for RS-485/422
OFF
ON
PanelView Modbus Connector
1 2
Not Used
1 5
9 6