HD48S... series
RS485 MODBUS-RTU
S
485
ETTING THE RS
STANDARD COMMUNICATION PROGRAM
Before connecting the transmitter to the RS485 network, an address must be assigned
and the communication parameters be set, if different from the factory preset.
The parameters setting is performed as follows:
x If you have the RS48 cable, install the drivers in the PC.
x Connect the transmitter to a PC USB port using the cable RS48 (or alternatively
through another USB/RS485 converter available, ensuring that their drivers are
installed in the PC).
x Move the ADDRESS jumper between the sign "ADDRESS" and "N = 0" to select
the configuration mode (see technical sheet to locate the jumper).
x Start a communication program such as Hyperterminal, and set the serial
communication parameters as follows (the instrument is connected to a COM port
type):
x Send the serial commands given in the following table to set the RS485 MODBUS
parameters:
Command
MA nnn
MB n
MP n
MW n
COMMUNICATION PARAMETERS OF THE TRANSMITTER WITH A
Baud rate: 115200
Parity: None
Data Bits: 8
Stop Bits: 2
Response
Description
&
Set RS485 address
Ranging from 1 to 247
Preset on 1
&
Set RS485 Baud Rate
n=0 Ÿ 9600
n=1 Ÿ 19200
Preset on 1 Ÿ 19200
&
Set RS485 transmission mode
n=0 Ÿ 8-N-1
n=1 Ÿ 8-N-2
n=2 Ÿ 8-E-1
n=3 Ÿ 8-E-2
n=4 Ÿ 8-O-1
n=5 Ÿ 8-O-2
Preset on 2 Ÿ 8-E-1
&
Set receiving mode after RS485 transmission
n=0 Ÿ Violates the protocol and gets in listen mode
n=1 Ÿ Respects the protocol and waits 3.5 characters
Preset on 1 Ÿ Respects the protocol
(8 data bits, no parity, 1 stop bit)
(8 data bits, no parity, 2 stop bits)
(8 data bits, even parity, 1 stop bit)
(8 data bits, even parity, 2 stop bits)
(8 data bits, odd parity, 1 stop bit)
(8 data bits, odd parity, 2 stop bits)
immediately after the transmission
after the transmission
- 1 -
ENGLISH
Rev. 1.2 – 25/09/2012
