| Value | Meaning | Description |
|---|---|---|
| 0 | Non-specific | There is no specific reason why the value is BAD. |
| 1 | Configuration error | The value is not useful because of some inconsistency regarding the configuration. |
| 2 | Not connected | The value is not reliable because the connection to the provider has been disconnected at consumer-side. For example, a communication driver actively disconnects from a PLC on user request or by design. |
| 4 | Sensor failure | The value is not useful because it cannot be converted. A value from the device (PLC) cannot be converted to the corresponding HMI tag. |
| 5 | No communication, with last usable value | The value is not useful because the communication to the data source failed, however a last known value is available. |
| 6 | No communication, no usable value | The value is not useful because the communication to the data source failed or has never been established since it was last out of service and a last known value is not available. |
| 7 | Out of service | The value is not reliable because the provider side has been disabled or shutdown. For example, a PLC is in stop mode or a tag is disabled for maintenance purposes. |