Protocol-level Modbus TCP connectivity check (FC3 probe) for a host and unit ID. On-prem only.
When to use
- Validate host/port/unit ID before scheduling poll workflows.
- Health-check a known PLC from a workflow or Dry Run.
Properties
| Property | Type | Description |
|---|---|---|
| IP Address / Host | text | Required. |
| Port | number | Default 502. |
| Unit ID / Slave ID | number | Default 1. |
| Timeout (ms) | number | Default 2000. |
| Probe register address | number | Holding register used for the FC3 probe. Default 0. |
Outputs
ok, responseTimeMs, optional Modbus exception metadata.