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Troubleshooting Devices
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Work through these in order. Each driver guide also has its own table.
1. Is the driver service running?
Open Driver Health. If the banner says Driver service offline, no network device can connect; demo, simulator and Local Tags still work.
- Try Restart Drivers on Appliance System. If it stays offline, contact Scada.Ink support or your integrator.
- The API server retries the connection to the driver service every 5 seconds and reconnects all devices once it's back.
2. Can the appliance reach the device?
- Run the Network Scanner on the device's subnet: if the port shows open, the network path is fine.
- The appliance needs an address in the device's subnet, or a route to it. Check VLANs and managed-switch port settings.
- If the scanner can't reach the subnet either, that's a network problem (VLAN, switch port, cabling) rather than something to fix from the appliance.
3. Is the driver configured the way the device expects?
Most "connects but reads Bad" problems are settings the wizard doesn't ask for: ControlLogix slot, S7 rack/slot and PUT/GET, FINS node, MELSEC frame type, Modbus unit ID and zero-based addresses, OPC-UA security and credentials. Check them under Settings → Driver Settings and see the driver guide. Saving a change reconnects the device.
Common symptoms
| Symptom | Likely cause | Fix |
|---|---|---|
| Card Offline, Driver Health Could not reach device at IP:port | Network, wrong IP/port, device refuses the protocol, or missing driver library. | Steps 2–3; read the driver log line for this device. |
| Connected but all values Bad | Wrong tag paths or protocol settings. If the device was actually unplugged or power-cycled, the driver should detect it and switch to Disconnected within about a polling cycle. | Check paths against the driver guide. |
| Some tags Bad, others fine | Those paths don't exist or aren't in the driver's syntax. | Compare with the driver guide; no validation happens when you add a path. |
| Values Uncertain | No data yet for that item (MTConnect, MQTT, HTTP path, SECS/GEM). | Check the item exists at the source. |
| One device goes to Error with a timeout message, others unaffected | A command to it took longer than 8 seconds (slow connect to a bad IP, huge browse) | Find the device with the wrong IP; avoid browsing very large controllers |
| Every device goes to Error at once, then recovers | The driver service itself restarted or stopped answering, not just one device's command | Check Driver Health for the service banner; try Restart Drivers on Appliance System |
| Device flaps Connected/Disconnected every ~10–30 s | Liveness check fails while reads work, or the device limits connections. | Modbus RTU: make sure holding register 0 is readable (it is read on connect and every poll). MELSEC: make sure D0 is readable (read on connect). Close other clients. |
| Status Error No data received for …s | No values stored for 300 s (static values with deadbands, or a stuck driver). | Remove deadbands on at least one changing tag; reconnect. |
| Polling Rate change ignored | Saving reconnects only a running device; a disabled device, or one stopped with Disconnect, uses the new rate the next time it connects. | Tick Enabled or click Connect. |
| Writes: Write access is not enabled for this device. Enable it in device settings. | Allow Tag Writes is off. | Turn it on under Settings → Tag Write Access. |
| Writes: You do not have permission to write to this tag. | Per-tag write permission. | See Tags and Users. |
| Writes: Failed to write tag | The driver or device rejected it (read-only address, wrong type, PLC mode). | Read the driver log. |
| Simulate does nothing | No subscribed tags, or your role isn't admin (errors aren't shown). | Subscribe tags; sign in as admin. |
| Device deleted by mistake | Deletion can't be undone. | Restore from a configuration backup (Backup) or recreate it. |
Reading driver error messages
Each driver prefixes its messages, e.g. [S7] Connection error: …, [Modbus] Read error for HoldingRegister/99: …, [FINS] Read error for D100: FINS error code: 0x1103, [ControlLogix] Batch read error: …, [OPC-UA] Connection error: …. Missing libraries appear as … not installed. These same messages are what you see in the device's error box on Driver Health, in Connectivity History, and from GET /api/driver-health/:id/log — no appliance access needed.