SE Modicon M580 Brochure

Modicon M580 automation platform Industrial Ethernet services Modicon M580 communication services

Functions (continued)

Functions (continued) I/O Scanning service

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Modicon Premium, M580, or Quantum platform with I/O Scanner function (Transparent Ready class p 30)

Word table Read

Write

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Ethernet Modbus/TCP

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Device with Modbus/TCP messaging in server mode

Device input words/ output words

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A

A

INPUT

INPUT

B

B

OUTPUT + –

OUTPUT + –

The I/O Scanning service is used to manage the exchange of remote I/O states on the Ethernet network after simple configuration, without the need for any special programming. I/O scanning is performed transparently by means of read/write requests according to the Modbus client/server protocol on the TCP/IP profile. This principle of scanning via a standard protocol enables communication with any device supporting Modbus TCP messaging in server mode. This service can be used to define: b A %MW word zone reserved for reading inputs b A %MW word zone reserved for writing outputs b Refresh periods independent of the PLC scan During operation, the module: b Manages TCP/IP connections with each remote device b Scans devices and copies the I/O to the configured %MW word zone b Feeds back status words used to check that the service is working correctly from the PLC application b Applies pre-configured fallback values if a communication error is detected A range of hardware and software products is available enabling the I/O Scanning protocol to be implemented on any type of device that can be connected to the Ethernet network. Characteristics b Under EcoStruxure Control Expert (1) software, each station can exchange a maximum of: v 120 write words v 125 read words b Maximum size in the PLC managing the service: v For BME p 58 pp 40 processors, 1 Kword %MW in inputs and 1 Kword %MW in outputs with the manager PLC limited to 64 stations v For BME p 58 pp 20 processors and Ethernet communication module BMENOC03 pp , 2 or 4 Kwords %MW in inputs and 2 or 4 Kwords %MW in outputs with the manager PLC limited to 128 stations I/O Scanning service diagnostics I/O Scanning service diagnostics can be performed in one of four ways: b Via the application program from a specific PLC data zone b From the setup software debug screen b From the PLC system diagnostic function displayed by means of a Web browser on a PC station b Using standard SNMP network management software

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I/O Scanning service diagnostics

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(1) Unity Pro software in earlier versions.

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