for me the Quality codes must be the same than OPC DA

0 means Bad but the error issue is not listed in the OPC qualities.

You can find the complete list here: https://www.opcsupport.com/link/portal/4164/4590/Article/5/What-are-the-OPC-Quality-Codes

Nico

Hi,

The list of variable status is described in the online help, in the topic related to the variable selector (where we have a column for that).

Variable Quality

The quality provides an indication of the validity of the variable's value. A variable may still have a valid real-time value even with a quality other than good. When a variable is used in an animation, if the quality is anything other than good, a special color or a question mark will be displayed instead of its value. The following abbreviations are used to indicate a variables' quality.

• Good - Indicated by a null value in the quality field.
• NS Not Set (Invalid) - The variable may still have a value but it is no longer being updated.
• NS DE Dependent - The variable is invalid because the variable from which it is derived is disabled.
• NS EXP Expression - The variable is invalid because one or more variables in the expression form which it is derived is invalid.
• NS OP Operator - The variable has been masked by the operator. This will happen if an Alarm is disabled in an Alarm Display.
• NS M[n] Masked - The variable has been masked by a SCADA BASIC program. The level of the mask [1 to 4] is also shown.
• NS DIS Disabled - The variable has been disabled by using the inhibit tick box in its configuration.
• NS COM Communication - The variable source is external, but unavailable (typically due to a communication failure).
• NS L< The value of the variable is less than its specified minimum.
• NS L> The value of the variable is greater than its specified maximum.
• NS FMT Format error. For example a floating point variable does not confirm to the IEEE format.
• NS WD Equipment life indicator not refreshed. (When using specialist variable treatment - WATCHDOGEQT.)

Unfortunately, the corresponding OPC Qualities are not described. I am sure I have seen such a correspondance somewhere, but I cannot find it.

To answer your first question, no, there is not a single way to evaluate and transmit the "quality" of a data. OPC DA has one definition, IEC 104 has another, DNP a 3rd one, IEC 61850, OPC-UA, BACnet...
As many definitions as there are high end data transmission protocols.

But within PcVue, all of these are mapped at best on our own list of variable status which is described in the online help and pasted below.

And OPC Qualities in particular are used by PcVue when exposing a variable as an OPC item (through PcVue OPC Server), when using the #_Q substitution, Quality sequences in the HMI. Web Services Toolkit quality list is also heavily inspired by OPC qualities.

Note for future: A good practice when documenting a data acquisition driver or a server interface is to document data quality mapping.

Any volunteer to help writing a bunch of KB articles ?

Come back on this topic 1 year later!
Ok we have the list of the different NS status but what about the number.
I would like to know the value written in the Quality column for each status.

Maybe only a developer can check in the code...

Nico

shuould be that, no?
https://www.opcsupport.com/link/portal/4164/4590/Article/5/What-are-the-OPC-Quality-Codes

I took 3 more minutes and found the correspondance in the a KB article:
https://support.pcvuesolutions.com/index.php?option=com_k2&view=item&id=243:the-quality-field-in-opc-and-the-hds&Itemid=25

We also have this one, older and less comprehensive:
https://support.pcvuesolutions.com/index.php?option=com_k2&view=item&id=77:quality-opc-flags-for-pcvue-opc-server&Itemid=31

Regards

That's not exactly what I have asked.
What I would like is a table like your second link (first is 404 btw) but more complete.
Something like

I try to find this information and will post it here.

Nico
Nico

This is exactly what the first link is about.
If the link is 404 for you, then simply search for KB243 in the KB.