Manufacturing Execution System (MES) Integration

Manufacturing Execution Systems (MES) offer many benefits including enhanced visibility into production, improved efficiency, cost reduction, and better inventory monitoring.

The Prism-Lente framework supports integration using industry standard protocol OPC-UA. Information about the OPC-UA standard is available from the OPC Foundation:

OPC-UA Integration

Operation

Currently the status information uploaded to the upstream Lente server are published. Values are updated every 10 seconds.

The OPC-UA server must be enabled in the settings.json file. See settings section for details.

For development and testing a free client is available from Unified Automation:

_images/Screenshot_mes_integration_uaexpert.png

Fields Published

  • cmd: Last command remotely executed

  • computer: Host name of host system

  • disk_usage: Percentage of file storage space consumed on drive where result files are stored

  • ip: IP address of host system

  • num_files: Number of result backup files are stored in result_bkup_dir

  • result_class: Not used

  • script (Prism only): Currently loaded Prism script (if any)

  • scripts_version: Version of the scripts directory

  • user: Currently logged in user (if any)

  • version: Version of the Prism/Lente base directory

  • clients (Lente only): Listing of downstream Prism/Lente systems and their attributes

Methods

  • restart: Restart Prism or Lente application; causes active users to be logged out.

Settings

opcua_server settings are defined in the settings.json.

Example settings:

"opcua_server": {
  "enable": true,
  "security_policies":[
    "NoSecurity",
    "Basic256Sha256_Sign",
    "Basic256Sha256_SignAndEncrypt"
  ],
  "certificates": {
    "enable": true,
    // "path": "public",
    // "certificate_file": "cert.pem",
    // "private_key_file": "key.pem",
  }
}

OPC-UA Server

Section Name: opcua_server

Location: settings.json under top level

  • enable: If true, start opcua_server

    • default: false

  • listen_address: IP address for opcua_server to listen

    • default: 0.0.0.0

  • listen_port_prism: TCP port for Prism opcua_server to listen

    • default: 4840

  • listen_port_lente: TCP port for Lente opcua_server to listen

    • default: 4841

  • security_policies: List OPC-UA security policies to permit clients to connect with

    • Possible values: NoSecurity, Basic256Sha256_Sign, Basic256Sha256_SignAndEncrypt

    • Default: NoSecurity, Basic256Sha256_Sign, Basic256Sha256_SignAndEncrypt

  • fields: List of fields to publish (null: publish all)

    • Default: null (publish all)

Certificates

Certificate and key files can be the same ones as used by Prism/Lente to secure access using HTTPS. See HTTPS and SSL Certificates.

Section Name: certificates

Location: settings.json under section ‘opcua_server’

  • enable: If true, use certificates

    • default: false

  • path: Path to directory where certificate and private key files reside relative to the Prism or Lente root path

    • default: public

  • private_key_file: File containing private key

    • default: key.pem

  • certificate_file: File containing certificate

    • default: cert.pem