Device Connectivity

Connect to industrial devices using OPC UA, Siemens S7, and EtherNet/IP protocols

Device Connectivity

DataForeman supports multiple industrial protocols to connect to your devices, collect data, and store it for analysis. The Connectivity module handles all device communication and data acquisition.

Connectivity Overview

Overview

The Connectivity module provides:

  • Multi-Protocol Support: OPC UA, Siemens S7, EtherNet/IP (Allen-Bradley PLCs)
  • Tag Browser: Visual interface to discover and select data points
  • Real-Time Monitoring: Live status indicator showing active connections
  • Auto-Discovery: Automatic device and tag detection (protocol-dependent)
  • Data Quality: Connection health and data quality indicators

Supported Protocols

OPC UA (OPC Unified Architecture)

Use Cases:

  • Modern SCADA systems
  • Industrial IoT gateways
  • Multi-vendor equipment integration

Features:

  • Browse server node tree
  • Subscribe to value changes
  • Secure authentication (username/password, certificates)
  • Automatic reconnection on network issues

Siemens S7

Use Cases:

  • Siemens PLCs (S7-300, S7-400, S7-1200, S7-1500)
  • Direct PLC communication
  • High-speed data collection

Features:

  • Read data blocks (DB)
  • Support for all S7 data types
  • Optimized batch reading
  • Slot and rack configuration

EtherNet/IP (Allen-Bradley)

Use Cases:

  • Rockwell Automation PLCs (ControlLogix, CompactLogix)
  • Allen-Bradley devices
  • Ethernet-based industrial networks

Features:

  • Multi-rate polling (different tags at different speeds)
  • Program-scoped tag browsing
  • Structure and UDT support
  • Connection rate optimization

Getting Started

Step 1: Navigate to Connectivity

Click the Connectivity icon in the left sidebar.

Step 2: Select Protocol Tab

Choose the protocol that matches your device:

  • OPC UA tab for OPC servers
  • SIEMENS S7 tab for Siemens PLCs
  • ETHERNET/IP tab for Allen-Bradley PLCs

Step 3: Create a Connection

  1. Click SETUP NEW CONNECTION
  2. Fill in the connection details (see protocol-specific sections below)
  3. Click Test Connection to verify
  4. Click Save to create the connection

OPC UA Connection Setup

Required Information

  • Connection Name: Descriptive name for this connection
  • Endpoint URL: OPC UA server address (e.g., opc.tcp://192.168.1.100:4840)
  • Security Mode: None, Sign, or SignAndEncrypt
  • Authentication: Anonymous, Username/Password, or Certificate

Configuration Steps

  1. Enter the endpoint URL of your OPC UA server
  2. Select security mode (start with “None” for testing)
  3. If required, enter username and password
  4. Click Browse Endpoints to auto-detect server capabilities
  5. Test the connection
  6. Save the configuration

Browsing Tags

Once connected:

  1. Go to the TAGS tab
  2. Select your OPC UA connection from the dropdown
  3. Expand the node tree to find your data points
  4. Select tags you want to monitor
  5. Click Add Selected Tags to start data collection

OPC UA Tag Browser

Siemens S7 Connection Setup

Required Information

  • Connection Name: Descriptive name
  • IP Address: PLC IP address (e.g., 192.168.1.50)
  • Rack: Usually 0 for most setups
  • Slot: Usually 1 for S7-300/400, 0 for S7-1200/1500
  • PLC Type: Select your PLC model

Configuration Steps

  1. Enter the PLC IP address
  2. Configure rack and slot numbers
  3. Select the PLC type from the dropdown
  4. Test the connection
  5. Save the configuration

Adding Tags

  1. Go to the TAGS tab
  2. Select your S7 connection
  3. Manually define tags with:
    • Tag name
    • Data block number (e.g., DB1)
    • Start byte (e.g., 0)
    • Data type (BOOL, INT, REAL, etc.)
  4. Click Add Tag to start monitoring

EtherNet/IP Connection Setup

Required Information

  • Connection Name: Descriptive name
  • IP Address: PLC IP address
  • Slot: Usually 0 for ControlLogix, varies for CompactLogix
  • Timeout: Connection timeout in milliseconds (default: 5000)

Configuration Steps

  1. Enter the PLC IP address
  2. Set the slot number (check your PLC configuration)
  3. Adjust timeout if needed for slower networks
  4. Test the connection
  5. Save the configuration

Browsing Tags

The EtherNet/IP driver supports automatic tag discovery:

  1. Go to the TAGS tab
  2. Select your EtherNet/IP connection
  3. Click Browse PLC to discover available tags
  4. Filter by:
    • Program name (for program-scoped tags)
    • Data type
    • Tag name pattern
  5. Select tags to monitor
  6. Click Add Selected Tags

Live Status Monitor

The LIVE indicator in the top-right shows:

  • Green (4/4): All connections active and healthy
  • Yellow (3/4): Some connections have issues
  • Red (0/4): No active connections
  • Gray: Connectivity service not running

Click the indicator to see detailed status for each connection.

Tag Management

Tag Settings Tab

The Settings tab provides system-wide configuration:

  • Poll Rates: Default polling intervals for each protocol
  • Batch Sizes: Number of tags to read in one request
  • Timeout Values: Connection and read timeouts
  • Retry Logic: Automatic reconnection settings

Multi-Rate Polling

For EtherNet/IP connections, you can configure different poll rates for different tags:

  • Fast (100ms - 1s): Critical process variables
  • Medium (1s - 10s): Standard monitoring tags
  • Slow (10s - 60s): Setpoints and status flags

This optimizes network traffic and PLC load.

Data Quality Indicators

Each tag has a quality indicator:

  • Good: Data is current and valid
  • Uncertain: Data may be stale or estimated
  • Bad: No communication or invalid data

Troubleshooting

Cannot Connect to Device

  1. Check Network:

    • Ping the device IP address
    • Verify firewall rules allow traffic
    • Check network cables and switches

  2. Verify Settings:

    • Confirm IP address is correct
    • Check rack/slot numbers (S7)
    • Verify endpoint URL (OPC UA)

  3. Protocol-Specific:

    • OPC UA: Check security mode matches server
    • S7: Ensure PLC has accessible data blocks
    • EIP: Verify slot number and communication path

Tags Not Updating

  1. Connection Status: Check live status indicator
  2. Tag Configuration: Verify tag addresses are correct
  3. Poll Rate: Confirm poll rate is appropriate
  4. PLC Program: Check if PLC is in RUN mode

Performance Issues

  1. Reduce Poll Rate: Slow down non-critical tags
  2. Batch Optimization: Adjust batch sizes in settings
  3. Connection Limits: Check PLC connection limits
  4. Network Load: Monitor network bandwidth usage

Best Practices

Security

  • Use secure authentication when possible
  • Limit network access to DataForeman server
  • Use VLANs to separate OT and IT networks
  • Regularly update PLC and server firmware

Performance

  • Group tags by poll rate (fast, medium, slow)
  • Use appropriate data types (don’t read DWORD for BOOL)
  • Limit total tag count per connection (< 1000 recommended)
  • Monitor CPU and memory usage in Diagnostics

Organization

  • Use clear, descriptive connection names
  • Follow consistent naming conventions for tags
  • Document rack/slot configurations
  • Maintain an inventory of connected devices

Next Steps