#12 Access to objects

[Anonymous]

Hello!
I have question about objects.
1) I can not write and read property to/from itself. And now have not special command for it? (I use yocto with meta-bacnet 0.8.4 (https://github.com/evensonbryan/meta-bacnet) )
bacserv 1234 (my first device)
(from 1234)> bacwp 1234 1 0 85 -1 16 100
or
(from 1234)> bacrp 1234 1 0 85
not working because meta has not CreateObject service or need special command?

I can read and write to/from second or any device in network:

(from 1234)> bacwp 1111 1 0 85 -1 16 100
OK
(from 1234)> bacrp 1111 1 0 85
OK

And if I send from 1111 to 1234 - bacwp 1234 1 0 85 -1 16 100, where value 100 saved on 1234 device (into temporary file)?

2) How I can send text msg not using bacarf?
3) If not my device connecting to my network it can get access to data or there are some methods of protection?

[Steve Karg]

1) See A-15 to Q-15 on frequently asked questions:
http://svn.code.sf.net/p/bacnet/code/trunk/bacnet-stack/doc/README.faq

2) WriteProperty to a CharacterString property, such as object-name, description, etc, or use a CharacterString Value object.

3) BACnet is designed for other devices to access your data. I suppose you could "lock" your data from others writing or changing it, but what is the purpose of BACnet if not to share your data?

[Anonymous]

Ok, thanks.
From fthird I neab protection against hacking and sending not valid control data to bacnet devices.

Can I send broadcast msg that for example all devices set to analog_output present_value 10?

[Steve Karg]

No, you cannot send a Broadcast WriteProperty. BACnet prohibits broadcast of any of the confirmed services. BACnet does support WritePropertyMultiple or WriteGroup (if the receiving devices support those services).