Siemens SIMOCODE pro C System Manual page 45

Communication via Modbus:
Modbus RTU (Remote Terminal Unit) is a standard protocol for network communication and
uses the electrical RS485 connection for serial data transmission between Modbus devices
in the network.
Modbus RTU uses a master/slave network in which the entire communication is triggered by
only one master device while the slaves can only respond to the request of the master. The
master sends a request to a slave address and only this slave address responds to the
command (exception: broadcast frames to slave address 0 that are not acknowledged by the
slaves).
SIMOCODE pro V Modbus devices have been developed in accordance with the "MODBUS
over serial line specification and implementation guide" (available at www.modbus.org
(http://www.modbus.org)). You can find the relevant information on establishing Modbus
RTU communication in this specification. The key points for a Modbus RTU communication
network ("Multipoint System requirements") listed in the specification apply equally for a
communication network with SIMOCODE devices.
See Chapter "Modbus communication" in the manual SIMOCODE pro - Communication
(https://support.industry.siemens.com/cs/ww/en/view/109743960).
Communication via EtherNet/IP:
EtherNet/IP (EtherNet Industrial Protocol, often simply called EIP) is a real-time Ethernet that
is used mainly in automation engineering. EtherNet/IP was developed by Allen-Bradley and
was later handed over to the Open DeviceNet Vendor Association (ODVA) as an open
standard. See Open DeviceNet Vendor Association (http://www.odva.org).
Besides PROFINET and Modbus/TCP, EtherNet/IP is an Ethernet-based fieldbus that is
currently widely spread.
SIMOCODE pro V EtherNet/IP devices were developed in compliance with the EtherNet/IP
standard and have the following properties:
● Integrated switch with two ports
● Media redundancy via Device Level Ring (DLR)
● System redundancy (as of E03).
See Chapter "EtherNet/IP communication" in the manual SIMOCODE pro - Communication
(https://support.industry.siemens.com/cs/ww/en/view/109743960).
SIMOCODE pro
System Manual, 05/2019, A5E40507475002A/RS-AD/004
Features
45