Sending Temp. setpoint via BACnet to a boiler

Hello everyone,
Hope all doing well,
I have a problem sending the temp. setpoint to a boiler through BACnet protocol.
I made the communication between the controller and the boiler and I can see all boiler parameters on my controller.
Trying to send the temp setpoint to the boiler but it doesn't make any change on the boiler control display.
I'm wondering if I'm missing something or choose wrong parameter which I need to find a writable data point to make changes on it.
The controller is Honeywell CP-EXPIO and the Boiler is Lochinvar AWH1250.
I really appreciate the help.

Thank you
 
Which object are you attempting to write to?

From what I believe is the relevant documentation (https://www.lochinvar.com/lit/57443... C_AWH Modbus Bacnet Manual (Add AWH_KBX).pdf), it seems there are two Analog Values for the setpoint: AV2 "0-10 Volt Input / Rate Command / Setpoint Command" and AV3 "Tank Setpoint" (note that the document actually shows AI in the table, but as it's under the Analog Values section, I think that's a typo).

Since BACnet allows Analog Values to be read-only, it's possible that AV3 may be read-only and is the current setpoint, while AV2 is writable and is the setpoint command (note, though, AV2 is in percent, while AV3 is in Deg C).

Also note that on page 10 of that manual, it states the following:
When the tank temperature and/or 0-10V BMS voltage is provided by the BAS to the appliance, it is critical that the values be updated every few seconds. If the appliance does not receive updated values within a timeout period (installer adjustable), the control will revert to using its own readings (if connected). The timeout is programmable by accessing parameter H6 (see the Armor Service Manual for instructions for setting parameters). The timeout is adjustable between 5 and 120 seconds. The default timeout is 10 seconds.

For further troubleshooting, I recommend using a USB to RS-485 adapter, your computer, and Yabe to connect to the boiler and see if you can write to the setpoint using Yabe or if any error messages are returned. You can download Yabe here:
https://sourceforge.net/projects/yetanotherbacnetexplorer/
 
Which object are you attempting to write to?

From what I believe is the relevant documentation (https://www.lochinvar.com/lit/574437100305786_2000558371_Rev C_AWH Modbus Bacnet Manual (Add AWH_KBX).pdf), it seems there are two Analog Values for the setpoint: AV2 "0-10 Volt Input / Rate Command / Setpoint Command" and AV3 "Tank Setpoint" (note that the document actually shows AI in the table, but as it's under the Analog Values section, I think that's a typo).

Since BACnet allows Analog Values to be read-only, it's possible that AV3 may be read-only and is the current setpoint, while AV2 is writable and is the setpoint command (note, though, AV2 is in percent, while AV3 is in Deg C).

Also note that on page 10 of that manual, it states the following:
When the tank temperature and/or 0-10V BMS voltage is provided by the BAS to the appliance, it is critical that the values be updated every few seconds. If the appliance does not receive updated values within a timeout period (installer adjustable), the control will revert to using its own readings (if connected). The timeout is programmable by accessing parameter H6 (see the Armor Service Manual for instructions for setting parameters). The timeout is adjustable between 5 and 120 seconds. The default timeout is 10 seconds.

For further troubleshooting, I recommend using a USB to RS-485 adapter, your computer, and Yabe to connect to the boiler and see if you can write to the setpoint using Yabe or if any error messages are returned. You can download Yabe here:
https://sourceforge.net/projects/yetanotherbacnetexplorer/
A much more thorough and detailed response than I could muster!
Yes, agreed.

I've integrated to very new Lochinvar boilers and it...leaves a lot to be desired. The BACnet points list is goofy and full of typos. Lochinvar is of little help as they just buy the BACnet comm card from a 3rd party, and have no involvement in the development.

When I did the integration, we did the setpoint over 0-10v hard-wired. I can't remember if I ever tried to tweak it over BACnet. Definitely try hooking up to it with YABE and see if you can. You may have to tried various things such as writing at a higher priority level.
 
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