ATC Mini Chiller Modbus Protocol v1 - 03 May 2019
1
ModBUS® Communication Protocol
for the
ATC MINI Chiller
Applied Thermal Controls Limited
Gee Rd, Coalville LE67 4NB
, UK
Email: [email protected]
Tel: +44 (0)1530 839998
OVERVIEW
The ATC MINI Chiller uses the ModBUS® RTU communication protocol over RS485 networks
All communication messages finish with a check sum type CRC (cyclic redundancy check).
Every slave device in a network must have a different address.
The protocol allows one master only and up to 247 slaves.
Only the master unit can start communication by the transmitting the address
of the intended slave unit and the command to execute.
Only the slave unit having the matching address will answer to the master.
Remote control via RS485 has priority over local MINI Chiller settings.
The serial transmission characteristics are programmable within
the ATC MINI Chiller Parameter Menu Modbus
Settings
Slave device address: 1 to 247
Baud rate: 4800, 9600, 19200, 38400, 115200 bits per second
Byte Format: 1 start bit, 8 data bits, optional parity bit (odd, even, none) and 1 stop bit
2 wire (half duplex) and 4 wire (full duplex) RS485 communication is supported
Termination resisters (120R) are required at each end of the RS485 network
Annex L-11M 190503 SA00011M RS485 ModBUS RTU for Mini
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