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Version: Next (unreleased)

SLMP (MELSEC) 3E

Description​

The adapter allows to connect devices supporting SLMP (MELSEC) 3E.

Configuration​

The following configuration options are available when creating an adapter:

PLC Address​

This field requires the PLC address in form of the IP without the prefixed protocol (e.g., 192.168.34.56).

Polling Interval​

The polling interval requires a number in milliseconds, which represents the interval in which the adapter will poll the PLC for new data. For instance, a polling interval of 1000 milliseconds will configure the adapter to send a request to the PLC every second.

If a read is still running when the next poll is due, that poll is skipped. Read requests are bounded to five seconds; configure driver request timeouts below this bound. After a failure, retries back off from one second up to sixty seconds. Successful reads reset this backoff.

Supported Transports​

The following transports are supported by this adapter:

  • tcp
  • test

Transport Metadata​

Required​

tcp

Advanced​

tcp

  • connect-timeout-ms: (INT)
  • read-timeout-ms: (INT)
  • write-timeout-ms: (INT)
  • no-delay: (BOOLEAN)
  • keep-alive: (BOOLEAN)
  • send-buffer-size: (INT)
  • receive-buffer-size: (INT)
  • local-address: (STRING)
  • local-port: (INT)

Protocol Metadata​

Required​

Optional​

  • monitoring-timer: SLMP monitoring timer written into each 3E request frame (0 = wait infinitely). (INT)
  • request-timeout-ms: Client-side timeout in milliseconds awaiting a response. (INT)

Tags​

The syntax to define tags is based on the PLC4X syntax, see https://plc4x.apache.org/plc4x/latest/users/protocols/s7.html. Address Pattern:

propertyName=%{Memory-Area}{start-address}[{start-index}..{end-index}]:{Data-Type}

temperature=%I0.0:INT

Browsing tags​

Choose Browse PLC tags after configuring the connection, then load Available tags and select the readable tags. The browse query defaults to * for S7 and ADS, which browse all available items with this query. For OPC UA, it defaults to ns=0;i=85 (the Objects folder). Children are loaded one level at a time as you expand folders, avoiding a recursive browse of the entire server. Enter a parent NodeId to browse its children, for example ns=2;s=Demo.Industrial.CncMachine.RawData, then select cycleActive from the results. A query for a leaf node returns its children, not the leaf itself. Earlier saved OPC UA queries using * are interpreted as the Objects folder. Include the server's endpoint path in PLC Address, for example localhost:4840/milo; the path is case-sensitive. Query syntax and returned information depend on the driver and PLC. Unsupported connections report an error; use Enter tags manually instead. Browsing waits up to ten seconds for the response and returns the connection to the shared cache afterwards.

The tree preserves the hierarchy supplied by the driver. Only readable items with an address can be selected. S7 browsing can return memory areas and data blocks as byte addresses rather than symbolic, typed variables. Use manual entry when you need different offsets, datatypes, or custom event field names.

Selected addresses are used unchanged for sampling and polling. Event field names start with tag_, followed by the address with punctuation replaced by underscores. Conflicting names require manual entry. Browsing is performed only while configuring the adapter; starting an adapter uses its saved selections without browsing again.

Upgrading existing adapters​

The version 3 migration keeps existing tags in the selected manual-entry option, preserving field names and addresses.

The version 2 adapter migration updates saved PLC4X configuration parameter names and legacy array addresses for PLC4X 1.0. For example, request-timeout becomes request-timeout-ms, and %DB42:28.0:BYTE[4] becomes %DB42:28.0[0..3]:BYTE. A single index selects a scalar; a range selects a list. S7 connections now use the s7 driver with the cotp transport. Rack and slot parameters use the cotp. prefix. Explicit configuration values are retained. Unspecified settings use PLC4X 1.0 defaults, including its certificate verification defaults. Review the PLC4X migration guide for protocol-specific changes before connecting to a device after an upgrade.

Best Practices​

Instead of creating a large event containing all nodes that should be available in StreamPipes, consider to group the fields logically into smaller adapters. This will ease the definition of pipelines for users and eases future modifications.

Last updated on by Dominik Riemer