1. Protocol Overview

• Protocol Description: HostLink is a serial communication protocol developed by Omron for its PLC products. "HostLink over TCP" is an implementation that encapsulates this serial protocol within TCP/IP, allowing host systems or gateways to access PLC data via Ethernet.
• Application Scenarios: This protocol is widely used in scenarios requiring remote monitoring, program transmission, and data acquisition for Omron PLCs (e.g., CP, CJ, and CS series) via Ethernet. It is a common method for connecting HMIs, SCADA systems, and IoT gateways to Omron PLCs.
• E2C Trinity Support: E2C Trinity supports connecting to Omron PLCs as a Client (Master) via Ethernet using the HostLink over TCP protocol to access PLC internal data areas (such as CIO, WR, HR, DM, etc.).

2. Prerequisites

Before starting the configuration, please ensure the following:

• Hardware Connection:
  • Ensure the E2C Trinity gateway and the target PLC are connected to the same Local Area Network (LAN) and can communicate.
  • The debugging PC must be connected to the same network to log into the E2C Trinity web interface.
• Network Parameters:
  • Obtain the IP Address and Port Number of the target PLC (typically configured in the PLC's Ethernet module settings).
  • Ensure the E2C Trinity gateway is on the same subnet as the PLC with no IP conflicts.
• Device Parameters:
  • Prepare the PLC project file or the Data Point List.
  • Identify key parameters:
    • Unit Number (HostLink Node Number): The station number of the target PLC.
    • Tag Addresses: Register addresses to be collected.
    • Data Type: Data type for each point (e.g., int16, float32, bool).

3. Configuration Steps

Follow these steps within the E2C Trinity web interface.

Step 1: Create Device

1. Log into the gateway management page. Navigate to [Data Acquisition] to enter the E2C Trinity configuration page.

1. Click the "Create Device" button and fill in the connection information in the pop-up window.

1. Click "Save" to complete the device creation.

Step 2: Configure Tag (Point Table)

1. Select the newly created device from the device list on the left.
2. Click "Add" to create a single data acquisition Tag. Fill in the tag information.

• For example, if the point address in the PLC is D100, configure the "Address Type" as "D" and the "Address" as "100".
• For example, to read the 3rd bit of the D100 register in the PLC, configure the "Address Type" as "D", the "Address" as "100", and the "Bit Offset" as "3".
• Repeat the steps to add all necessary tags. Once finished, click the "Publish" button in the top right corner to apply the configuration.

4. Verification & Troubleshooting

Verification

1. Check the device list to ensure the status is Online and tags are successfully collected.

1. View the Latest Value column to verify data accuracy.

1. Test Writing: Click the edit icon in the "Latest Value" column, modify the value, and verify if the PLC accepts the change in the next polling cycle.

Common Troubleshooting (FAQ)

• Issue: Device remains offline.
  • Verify physical Ethernet cable connections.
  • Use the Ping tool in [System -> Tools] to check if the PLC is reachable.
  • Double-check the Port Number; ensure the PLC's Ethernet module is configured to listen on this port for HostLink requests.
• Issue: Connected, but values are null or incorrect.
  • Verify Address and Data Type: Ensure the "Address Type" and "Address" match the PLC program exactly.
  • Check [Debug Logs] to filter by device and identify specific error details.

5. Appendix: Data Type Mapping

When configuring tags in E2C Trinity, use the following mapping:

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