Modbus Communication Interface | A-3
ANALYZER MODBUS INTERFACE PARAMETERS
A number of analyzer Modbus interface parameters need to be set up in order to establish
communication with the Modbus master. These parameters are accessed via the service
port on the analyzer using a service program running on a PC.
Modbus Address
The analyzer needs to be assigned a Modbus slave address, which can be a number from 1 to
247 with 0 interpreted as a broadcast address (Meaning that analyzer will execute the com-
mand but will not send a respond back to the MODBUS master).
Communication Parameters
The number of data bits is always 8; the baud rate is 9600 or 19200, the number of stop bits,
and the parity of the analyzer MODBUS serial communication port are software selectable.
The default communication parameter settings are 9600 baud, 1 stop bit and EVEN parity. A
variable called ParityAndStop located in holding register 31 with MODBUS slave address of
4032 determines the port settings.
Power should be recycled or a reset command should be issued to activate the slave address
or parity and stop bit change.
The baud rate change will take effect immediately.
Figure A-2.
Communication Parameters
VALUE STOP BITS PARITY
0 1 None
1 2 None
2 1 Even
3 1 Odd
To Next Page
Loading...
Need help?
General
