#27 Error while running demo server

[Anonymous]

We were planning to working on read-write operations from a bacnet device which is simulated through bacnet protocol stack.As a beginner in the field we have downloaded the Bacnet protocol stack in our ubuntu 16.04 system for Data simulation and on terminal executed make clean all and make BACDL_DEFINE=-DBACDL_MSTP=1 clean all.
I started the demo server in terminal with demo/server/bacserv 3456 . But the output shows a USB0 error.(...see attached image)
Also tried the demo/whois/bacwi -1 to list the devices on the same system on seperate terminal but with no success.

Can someone help on why this error occurs and a solution for this?

[Steve Karg]

What is the device name for the RS485 device? By default, the MS/TP build for Linux uses /dev/ttyUSB0 as the device. If it's not connected or has another name, then an error will be printed.