FIELDBUS Network

***********What is HART Protocol?
HART protocol communication is half-duplex. The host can communicate with a field transmitter and the field transmitter can communicate back to the host. However, there is a single communication line across the 4-20mA loop, and only one or the other can send commands or data at any given time 

https://www.youtube.com/watch?v=pXkun-PEiY0
DCS Distribute Control Systems
PLC Programmable Logic Controller
16 bits 65,535
0-1000 psi
each bits represent
1000/65,535 =0.015 psi
encode digital data at 1200 Hz and 2200 Hz
AFSK audio frequency shift keying

*********What is BACnet?
BUILDING AUTOMATION AND  CONTROL NETWORK

BACnet / Modbus - Converter
https://www.youtube.com/watch?v=Hqh-X2LnkRg
https://www.youtube.com/watch?v=GoKR0eezVCc

use MS/TP
master slave token pass
3 wires rs485
NETCOM 

PN/BACnet Link: Data exchange between PROFINET and BACnet networks
https://www.youtube.com/watch?v=7h6ZksLhMQg

**BACnet / Modbus - Converter

HD67671 is a BACnet Slave / Modbus Master Converter
HD67672 is a BACnet Slave / Modbus Slave Converter
HD67712 is a BACnet Master / Modbus Slave Converter
HD67671-IP, HD67672-IP, HD67712-IP supports both BACnet/IP and BACnet/Ethernet

The connection to BACnet is done over RS485.
The connection to Modbus is done over RS232 or RS485.