NOVUS N1040i Indicator - Manual (Page 6)

N1040i Indicator
NOVUS AUTOMATION 6/6
APPENDIX 1 - SERIAL COMMUNICATION
The indicator may be supplied with an asynchronous serial
communication RS-485 interface, with a master-slave connection for
communication with a host computer (master). The indicator is
always the slave. The communication is always initiated by the
master, which sends a command to the slave address with which to
communicate. The addressed slave recognizes the command and
sends a response to the master. The indicator also accepts
broadcast commands.
CHARACTERISTICS
• Signals compatible with RS-485 standard. MODBUS (RTU)
Protocol. Two wire connection between 1 master and up to 31
(addressing up to 247 possible) instruments in bus topology.
• Communication signals are electrically isolated from the INPUT
and POWER terminals. Not isolated from the retransmission
circuit and the auxiliary voltage source when available.
• Maximum connection distance: 1000 meters.
• Time of disconnection for the controller: Maximum 2 ms after last
byte.
• Programmable baud rate: 1200 to 115200 bps.
• Data Bits: 8
• Parity: Even, Odd or None
• Stop bits: 1
• Time at the beginning of response transmission: maximum 100
ms after receiving the command.
The RS-485 signals are:
D0
Bi-directional inverted data line.
Other names: D/, D- or A
D1
Bi-directional data line.
Other names: D, D+ or B
GND
Optional connection that improves the performance
of the communication.
CONFIGURATION OF SERIAL COMMUNICATION PARAMETERS
Three parameters must be configured in the device for serial
communication:
bavd
: Communication speed.
Prty : Parity of the communication.
addr : Communication address for the indicator.