Ethernet Communications Overview

The RMC75E, RMC150E, and RMC200 provide Ethernet communications. The RMC performs as a slave, requiring a master to control it. The RMCs support multiple simultaneous TCP connections. This means multiple devices can communicate with the RMC at the same time, using any of the supported protocols listed below.

Using Ethernet Communications

The RMC Ethernet can be used in several ways:

Communicating from RMCTools

RMCTools can communicate directly with the RMC over Ethernet. This connection provides the fastest update rate for registers and plots in RMCTools. Ethernet also provides the ability of remotely connecting to an RMC. See the Using Ethernet with RMCTools topic for details.

Note: When you first set up the controller, it is easier to use the USB port for communicating with the RMC from RMCTools than Ethernet because USB does not require setting up an IP address.

RMCTools uses port 44818. If your PC has a firewall, make sure it allows connections to port 44818. If the RMC is behind a firewall, make sure the firewall forwards port 44818 to the RMC’s IP address.

Communicating from PLCs, HMIs, and Other Devices

Communicating with the RMCs from PLCs, HMIs, or other master Ethernet controllers can be done in one of several methods:

• PLC Ethernet Emulation

The RMC responds to several common industrial Ethernet protocols and can emulate, or act like, several common PLCs. If your device supports reading and writing to registers in any of these PLCs, then your device should be able to communicate with the RMC. See Using the RMC’s PLC Ethernet Emulation for details.

• Standard Industrial Ethernet Protocols

The RMC controllers support several common industrial Ethernet protocols, including Modbus/TCP, PROFINET and EtherNet/IP. If your device can make requests in any of the RMC’s supported industrial Ethernet protocols, then it can likely communicate with the RMC. See the Supported Ethernet Protocols section below for details.

• .NET Assembly or ActiveX Control

Applications that are running on a Windows PC and that support .NET Assemblies, ActiveX Controls, or Microsoft Component Object Model (COM) can use Delta’s RMCLink .NET Assembly and ActiveX Control. See the RMCLink topic for details.

• Direct over TCP or UDP

Third-party or custom controllers that do not support any of the above three methods but can send and receive either TCP or UDP packets directly can communicate with the RMC by manually building and parsing packets over TCP or UDP, using Delta's simple DMCP protocol. See the Communicating Directly over TCP and Communicating Directly over UDP topics for details.

If your PLC, HMI or other device does not support any of the above methods, please contact a Delta Motion sales engineer to discuss your device. Delta strives to support all major Ethernet devices, and is interested in knowing about devices that the RMC does not support.

Note: The RMC does not support any of the native Ethernet protocols built into Windows.  That is, it does not support Web browsers, FTP, e-mail, and browsing through Network Neighborhood.

Configuring the RMC Ethernet Communications

Setting up the RMC Ethernet communications usually requires entering only a few TCP/IP parameters. Additionally, advanced users can choose to disable auto-negotiation and instead manually choose 10 or 100 Mbps and full- or half-duplex.

See the RMC Ethernet Setup topic for details.

Supported Ethernet Protocols

The RMCs support the Ethernet protocols listed below. It is not necessary to select in the RMC the application protocol or device with which you will be communicating. The RMC will automatically respond to all supported protocols.

If your Ethernet device supports one of the protocols listed above, then it may be able to communicate with the RMC. Read more about the protocols to make sure. There may be subtle problems with using some devices with the RMC. For example, a device that proclaims Modbus/TCP support may only be a slave device, and since the RMC is also a slave, neither device will initiate transfers, preventing the devices from being able to work together.

For a list of PLCs known to be compatible with the RMC, see the Using the RMC’s PLC Ethernet Emulation topic. For lower-level details on the supported protocols, see the RMC Ethernet Protocols topic.

Troubleshooting Ethernet

The Event Log and Communication Statistics provide information that can help troubleshoot the Ethernet communications.

Unreliable RMCTools Connections

Slow or poor Ethernet connections between RMCTools and an RMC may cause lost connections. Use the Communications: Ethernet section of the RMCTools Options dialog to choose Ethernet timeouts intended for slow connections.

Wiring

Ethernet cables that go outside the control cabinet or can be exposed to transients from motor drives or other switched loads should be shielded to avoid communication interruptions.

For the RMC75E, RMC150E, and RMC200 use straight-through Cat5, Cat5e, or Cat6 Ethernet cable with an RJ45 connector.

Ethernet Straight Through (8-wire) Cable

See Also

Communications Overview

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