Ethernet Communications; Embedded Ethernet Interface - GE PACSystems RX7i Reference Manual

Chapter 5. Communications
5.1

Ethernet Communications

For details on Ethernet communications for PACSystems, please refer to the following manuals:
PACSystems RX7i, RX3i and RSTi-EP TCP/IP Ethernet Communications User Manual, GFK-2224
PACSystems TCP/IP Ethernet Communications Station Manager User Manual, GFK-2225.

5.1.1 Embedded Ethernet Interface

RX3i
RX3i CPE302, CPE305, CPE310, CPE330 and CPE400 CPUs provide one or more embedded Ethernet
interfaces. If used, each interface connects to a Local Area Network (LAN).
The corresponding RJ45 Ethernet port(s) automatically sense the data rate on the attached LAN (1 Gbps,
100 Mbps or 10 Mbps), as well as the corresponding communication mode (half-duplex or full-duplex),
and the corresponding cabling arrangement (straight through or crossover). Automatic detection greatly
simplifies installation procedures.
See RX3i CPU Features and Specifications or RX7i CPU Features and Specifications to determine the
complete list of Internet protocols supported by each CPU.
Some important protocols supported by all RX3i CPUs are:
•
TCP/IP, which provides basic Internet capabilities;
•
SRTP, which is proprietary and which provides the interface with the PME programming and
configuration software and supports communications with certain control systems and
supervisory computer layers in the factory;
•
Modbus/TCP, which supports the Modbus messaging structure over the Internet.
On the CPE302/CPE305/CPE310 models, the same shared processor performs both Ethernet port
processing and Controller logic processing.
On the CPE330, the dual core CPU enables communication to be handled by one core while CPU logic
and I/O scanning is handled by the second core. Furthermore, each LAN interface is controlled by a
dedicated Network Interface Controller (NIC). In the CPE400, one of the four microprocessor cores is
dedicated to handling the communications function (LAN1, LAN2 and LAN3).
As a result of the hardware advances in the CPE330 and CPE400, a higher level of processing power is
provided in support of each LAN. This is especially important at higher data rates. It also offloads the
handling of Ethernet-level activity from the processor core tasked with performing CPU logic and I/O
scanning, permitting that core to run more efficiently.
Each interface on a LAN must have a unique IP Address and a non-overlapping IP subnet. This is
configured in PME. Care must be taken to survey the entire connected network architecture in order to
tabulate the IP addresses and IP subnets already in use, both on the local networks and on any of its
routed subnets connected with a gateway. Never assign a conflicting IP Address or configure duplicate
IP subnets.
182 PACSystems* RX7i, RX3i and RSTi-EP CPU Reference Manual GFK-2222AD