Hostlink (Omron)
Hostlink (Omron Serial)
The Hostlink driver enables communication with Omron PLCs via RS232 or RS422/485 serial ports using the ASCII-based C-Mode (Host Link) protocol.
Connection Settings (Network Settings)
These settings must exactly match the PLC’s Dip-Switch or PLC Settings.
Warning: The Omron Hostlink protocol defaults to 7 Data Bits, 2 Stop Bits, and Even Parity, which differs from the standard 8-N-1 configuration. If the connection fails, verify these parameters first.
| Parameter | Description | Example |
| Serial Port | COM port connected to the PLC. | COM1 |
| Baudrate | Communication speed (e.g., 9600, 19200). Must match the PLC setting. | 9600 |
| Parity | Parity check. Standard Omron setting is Even. | Even |
| Stop Bits | Stop bit count. Standard Omron setting is Two. | Two |
| Data Bits | Number of data bits. Standard Omron setting is 7. | 7 |
| Delay (ms) | Query delay: Minimum wait between requests to prevent collisions on RS485 networks. | 100 |
| Timeout (ms) | Maximum wait time for a PLC response. Adjust according to cable length and baudrate. | 250 |
| Retry Count | Number of retries before entering Fault state on communication failure. | 3 |
Device Settings
| Parameter | Description |
| Address | Unit Number: PLC’s Host Link Unit No (0–31). Typically 0 for direct connection. |
| Symbol | Project symbolic name for the device (e.g., Device1). |
| Enable | Activates or deactivates the device. Multiple conditions can be defined; if any are true, the device is active. Leave empty for always active. |
| Skip After Failure | Recommended to enable (True). If no response is received (Timeout), SCADA skips remaining tags for this device and moves to the next device, preventing RS485 network slowdowns. |
| Maximum Word Count | Maximum number of Words (Registers) read in a single request. Default: 125. Reduce (e.g., 32 or 64) for older FX series or noisy lines to improve reliability. |
| Connected | Bit becomes True when communication with the PLC is established. |
| Fault | Bit becomes True if a communication error occurs. |
| Comment | Optional note or description for the device. |
Addressing Table
Wise SCADA supports the following memory areas for Omron Hostlink.
Bit Addressing
Omron bit addresses range from .00 to .15 (e.g., DM 100.05).
| Address Type | Data Type | Description | Example |
| IR / CIO | Word/Bit | Inputs, Outputs, and Core Internal Relays. | IR 0, IR 100.0 |
| DM | Word | Data Memory (most commonly used area). | DM 0, DM 100 |
| WR / W | Word/Bit | Work Relay. | W 0, W 10.00 |
| HR | Word/Bit | Holding Relay (Retentive). | HR 0, HR 5.0 |
| AR | Word/Bit | Auxiliary Relay (System Bits). | AR 0, AR 10 |
| LR | Word/Bit | Link Relay. | LR 0, LR 10 |
| TK | Bit | Task Flag. | TK 0 |
| TS | Bit | Timer Status. | TS 0 |
| CS | Bit | Counter Status. | CS 0 |