Writing to BACnet properties
It is also possible to write values to BACnet properties via the BACnet/WS. A browser uses the GET method to do requests against the web services. To write a value to the web services, one needs to use the PUT method.
Fiddler can be used to do PUT requests, as well as POST and DELETE.
When writing to BACnet properties, one needs the address and path to the BACnet property and a payload, with the value to set. The "priority" parameter is set to 8, meaning "Manual operator". Consult the BACnet standard for more information about the priority levels. The "priority" parameter defaults to 16, if not used in the query.
Example XML: Lets say that the IP of the DINGO device is 192.168.1.69 and there is a relay, defined as "binary-output,1", in the BACnet server. Turning the relay on, can be achieved by entering this address and query into Fiddler:
http://192.168.1.69/bacnetws/.blt/binary-output,1/present-value?alt=xml&priority=8
And with this payload:
<Unsigned value="1" />
To turn the relay off, use this payload:
<Unsigned value="0" />
To release the priority level, use this payload:
<Null/>
Example JSON: Lets say that the IP of the DINGO device is 192.168.1.69 and there is a relay, defined as "binary-output,1", in the BACnet server. Turning the relay on, can be achieved by entering this address and query into Fiddler:
http://192.168.1.69/bacnetws/.blt/binary-output,1/present-value?alt=json&priority=8
And with this payload:
{ "$value" : "1" }
To turn the relay off, use this payload:
{ "$value" : "0" }
To release the priority level, use this payload:
{ "$base": "Null" }
Example PLAIN: Lets say that the IP of the DINGO device is 192.168.1.69 and there is a relay, defined as "binary-output,1", in the BACnet server. Turning the relay on, can be achieved by entering this address and query into Fiddler:
http://192.168.1.69/bacnetws/.blt/binary-output,1/present-value?alt=plain&priority=8
And with this payload:
1
To turn the relay off, use this payload:
0
The priority level can not be released with the PLAIN format.