OPC Quality Values

Overview

When OPC quality is reported in the logger, it will display the HEX code as in the following example:

Item Data for "DATE_TIME[0]": Value=2019 Q:0x00C0 VT=0x0003 ID=109429512

The following table maps the HEX codes to the quality description for reference.

Quality Name	Description	Code (HEX)
BAD		0x0
UNCERTAIN	This is used during RTU Configuration sequences (Enron Modbus and Benchmark, for now) when/if the RTU configuration object becomes invalid	0x40
GOOD	Good communication, a standard item, or the item’s value is known.	0xC0
CONFIG_ERROR	This is used when an item is valid in the protocol syntax, but rejected by the device (as in ROC and BSAP). It is also used if a configuration change makes a previously valid item become invalid (such as when changing a register set in Modbus). This is also used if a device returns an error while a protocol is in the RTU Configuration Write sequence.	0x4
NOT_CONNECTED		0x8
DEVICE_FAILURE		0xC
SENSOR_FAILURE		0x10
LAST_KNOWN	This is used when communication to a device has failed or produced an error and the item does has a previous value.	0x14
COMM_FAILURE	This is used when communication to a device has failed or produced an error and the item has no previous value.	0x18
OUT_OF_SERVICE		0x1C
WAITING_FOR_INITIAL_DATA	This is new in OPC 3.0 and should be the first quality assigned except for standard items and other items whose value is known immediately.	0x20
LAST_USABLE		0x44
SUB_NORMAL		0x58
LOCAL_OVERRIDE		0xD8