Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL - Manual (Page 140)

Installation and Wiring 9–11
Publication 2706-6.1
When the RS-485 port is configured for Open protocol
communications, the RS-485 port connects one or multiple DL40
Plus displays to a host controller (PLC, SLC, computer, etc) for
serial message triggering. This RS-485 network link supports
multi-drop communications with up to 127 DL40 Plus displays on
the link. We recommend you use Belden 9842 cable at a maximum
length of 4,000 ft (1219 meters).
The following diagram shows a typical RS-485 network with
multiple DL40 Plus displays.
COM
Belden 9842 Cable
Recommended
CH. A
CH. B
To Host Controller
To Next Node
RS-485
Shield
COM
CH. A
CH. B
Shield
COM
CH. A
CH. B
Twisted Pair
User installed jumper at first
and last DL40 Plus (physical
location) on the RS-485 link.
User installed jumper at any
one node only on the RS-485 link
User installed jumper at first
and last DL40 Plus (physical
location) on the RS-485 link.
First DL40 Plus On Network
Last DL40 Plus On Network
1 - E GND 2 - SHLD 3 - COMM 4 - CH A 5 - CH B 6 - TERM
RS-485
1 - E GND 2 - SHLD 3 - COMM 4 - CH A 5 - CH B 6 - TERM
Connecting the RS-485 Port
for Open Protocol