Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 39)

Publication 1753-UM001C-EN-P - March 2010 39
Installation Chapter 2
GuardPLC 1600 and GuardPLC 1800 Controllers
Connections for safety- and non-safety-related communication are
described in the following sections.
Connections for Safety-Related Communication
The controller has four 10/100BaseT, RJ-45 connectors to provide
communication via the GuardPLC Ethernet network to other
GuardPLC controllers, distributed I/O, and RSLogix Guard PLUS!
software. These connectors also provide communication via an
EtherNet/IP network to other Ethernet devices. Connectors 1 and 2
are located on the bottom side on the left. Connectors 3 and 4 are
located on the top side on the left.
All four connectors and the GuardPLC controller are connected
together by an internal Ethernet switch. In contrast to a hub, a switch
is able to store data packets for a short period of time to establish a
temporary connection between two communication partners for the
transfer of data. In this way, collisions (typical of a hub) can be
avoided and the load on the network is reduced.
The switch automatically switches between transfer rates of 10 and
100 Mbps and between full- and half-duplex connections. This makes
the full bandwidth available (full-duplex operation) in both directions.
A switch enables several connections to be established at the same
time and can address up to 1000 absolute MAC addresses.
Auto-crossing recognizes that cables with crossed wires have been
connected and the switch adjusts accordingly. Therefore, either
cross-over or straight-through Ethernet cabling can be used.
Star or line configurations are available. Make sure that a network
loop is not generated. Data packets must only be able to reach a node
via a single path.
L- L- L+ L+
COMM1
MODBUS
RS-485
24V DC
COMM2 COMM3
GuardPLC Ethernet
10/100 BaseT
ASCII/HSP
3 (—) 4 (—)
1 (—) 2 (—)
Ethernet Ports 3 and 4
Ethernet Ports 1 and 2