Hi,
The best way to troubleshoot is to use the Helper and check what happens with Wireshark.

Nico

Hi,

First I wish you all the best for this new year.

To be able to map a trend-log to a variable, the trend-log object needs to be configured with an output variable (property named "Log_DeviceObjectProperty"). I supposed it is not configured in the honeywell device (sorry I can't see it in your screenshot).

Hope it helps.

Hello Team,

Customer has requested for clarification on the importance of the "Log_DeviceObjectProperty" in Trendlog for configuring trends in PCVUE software. He understand that we are been able to import trends into the software without this property and he would like to better understand the reason for this.

Note: For your reference both DDC trend-log is attached from yabe.
Schneider DDC AHU TRENDLOG

Hi Nitesh,

If I am not mistaken, this property contains the name of the Object Property to store in the trendlog buffer.
For example, if you want to store the property Present-Value of the Analog Input number 10, then this PropertyReference must be set to the Trendlog "Log_DeviceObjectProperty" property.
PcVue needs to read this property to know which Pcvue variable must be used.

Extract from Ashrae:
12.25.8 Log_DeviceObjectProperty
This property, of type BACnetDeviceObjectPropertyReference, specifies the Device Identifier, Object Identifier and Property
Identifier of the property to be trend logged.
A change of the value of this property shall cause all records in the log buffer to be deleted and Records_Since_Notification
to be reset to zero. Upon completion, this event shall be reported as a BUFFER_PURGED log-status log record in the log
buffer as the initial entry regardless of the state of the log buffer before the change.
If this property is writable, it may be restricted to reference only objects inside the device containing the Trend Log object. If
the property is restricted to referencing objects within the containing device, an attempt to write a reference to an object
outside the containing device into this property shall cause a Result(-) to be returned.

Nico

Hello Team,
Please find the attached images of Trendlogs captured in YABE.
The customer is asking why the trendlog in Honeywell can be seen through YABE but not in PcVue.
As well as he states that these Honeywell Trendlogs can be seen in also thrid-party BACnet apps also.

Hello,

You can see the same thing if you use the Helper (right clic on the device).
But, as PcVue is scada software and not a BACnet browser, to be able to archive the data from the trendlog into an archive unit, PcVue needs a variable (to configure a trend) and the variable needs a BACnet objet (such as the Analog output or Analog Input ).
To retrieve this object, PcVue reads the Log_DeviceObjectProperty property of the trendlog bacnet object of the device as Nicolas explained below.
If the Log_DeviceObjectProperty is empty, PcVue won't be able to get the buffer and store it in a archive unit.

Hope it is clearer.

Hello Team,

Please find the attached BACnet PICS of Honeywell DDC.
The customer is verified with other SCADA that the trendlog feature is working well without the "Log_DeviceObjectProperty".
Please let us know if this property is mandatory to be in DDC for working of the Trendlog feature.

Hi,

I think better we talk. I will contact you.
Nico

Hi,

I had a brief discussion with Mansoor and suggested him to post an update to this thread.
I could not answer at once and let me rephrase it my way:

Regarding Trendlog standard, is Log_DeviceObjectProperty mandatory or optional?
I guess it is optional.

This being said, in PcVue mechanism, we need this Log_DeviceObjectProperty to be able to know the BACnet object and refer to the corresponding PcVue variable.
As a conclusion, if this Log_DeviceObjectProperty is empty/NA, PcVue cannot guess anything and cannot go further.
Meaning, either it has to be configured as expected by PcVue otherwise, it wouldn't move on.
If the device don't have such property or if the property is available but the SI/End user doesn't want to change it, it is the end.

Hi Edouard,

Yes, the property is optional but only at one condition (extract from Ashrae)
This property is required if, and shall be present only if, the monitored property is a BACnet property.

For this device, the Log_DeviceObjectProperty is not present in the Pics therefore we can guess the trendlog is populated by an internal program of the device.

But, to come back to the conlusion, yes PcVue needs this property to know what variable must be mapped to the trendlog but why not adding in PcVue the possibility to assign manually the variable? I think that's the solution...
And, it appears that Brice made a SPR as this issue happened already!! (#66075)
It has been assigned to be implemented in the 16.x version

Nico