Delta RMC101 - Manual (Page 370)

RMC100 and RMCWin User Manual
5-120
compared to the total cost of the system and gives much higher reliability.
• Upgrade to Smarter Switches.
EtherNet/IP utilizes IP multicasting, and as such uses a protocol called IGMP (Internet Group
Management Protocol). Most low-cost switches do not utilize IGMP to control which ports care
about the multicast packets, but instead broadcast multicast packets to all ports. This increases
the load on all segments of the network, which will increase collisions on half-duplex segments
and increase the possibility of overruns. By choosing switches that support IGMP (often called
IGMP Snooping), you can reduce the load on your network components and thereby increase
your determinism. However, notice that most of these switches require a router to be present in
the network for the IGMP snooping to work. Therefore, if your system will not always have a
router present, then you should purchase a switch that supports IGMP snooping without a router
present.
5.2.6.4 Modicon Quantum
5.2.6.4.1 Using Modicon PLCs with the RMC Ethernet Module
As of this writing, Modicon does not have Ethernet built in to any of its PLCs. However, it does
have an Ethernet TCP/IP module which can be added to the Quantum PLC backplane. Modicon
also is rumored to be working on a Momentum PLC with Ethernet TCP/IP capabilities. Our
understanding is that both PLCs will use the same method to communicate over Ethernet.
The module required for communicating via Ethernet with the Modicon Quantum is called the
Modicon Quantum Ethernet TCP/IP Module (140 NOE 211 00). It fits directly into the Modicon
Quantum backplane.
The Modicon Quantum Ethernet TCP/IP requires the following versions of Modicon products:
• Quantum Executive 2.0
• Modsoft 2.31
• Concept 2.0
• Modlink 2.0
If you are adding Ethernet TCP/IP to an existing Modicon Quantum PLC with the older Executive,
you will need to upgrade to the new Quantum Executive, which may require converting existing
Modsoft and Concept projects.
Follow the instructions in the Modicon Quantum Ethernet TCP/IP Module User Guide (840 USE
107 00) for installing and configuring the module.
If you need help setting up your network, either consult your network administrator, or for simple
stand-alone networks, see Setting up a Stand-alone TCP/IP Control Network.
The MaSTeR (MSTR) ladder logic block is used to read and write registers in remote devices
over Ethernet. The RMC has 65536 registers that can be read and/or written. Refer to the RMC
Register Map (Modbus/TCP and Modbus/RTU) topic for a map of the register addresses. Refer to
the following topics for details and examples on using the MSTR block:
• Using the MSTR Modicon Ladder Logic Block