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#9 PTP problems
Hello all,
On trying to see some BACnet communication I tried the
following:
On an XP Pro SP2 machine I installed VTS 3.4.9 with
WinPcap 3.1. I created a new port and set it up to be a
PTP port on COM1 with 9600 Baud. Then I connected COM1
to COM2 using a null modem and used a Terminal program
to listen to COM2. When I enable the PTP port and apply
this new setting, I see the message "BACnet" is
received on COM2. However, when I try to send any
message after that (Raw data or e.g. an "I am" message)
I get no data on COM2. What am I doing wrong? Or is
this simply not possible, or is this a new bug? Anyone
care to help me on this?
With kind regards,
Jos Bouwman.
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Jos,
I am not sure how VTS will behave as I have not tried it
however, in order to connect via PTP, BACnet requires a
negotiation process between devices. The "BACnet" string
you see is the request by one of the devices to start the
process. The receiving devices should then issue a binary
request to establish a connection. The rest of the
process is in binary and can not be viewed by a terminal
viewer.
My question to you would be which device has issued
the "BACnet" string? Did you see any other communication
that appeared to establish a connection? I am not sure VTS
will establish a connection automatically. You might have
to send the appropriate connection packets manually.
Let me know what you find out.
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Hello Lori,
Your comment is very usefull. I have no other devices
installed. So the BACnet string came from VTS. I will try to
use a second VTS instance to connect to COM2 and try to
start some communication. As you told, there might be a
change that I have to start communication manually. I'll
try. If I have time left and it worked, I'll give you a full
report.
Regards,
Jos Bouwman.