Arthur Grillo DPC200-MOD, Installation And Operation Manual, Page: 14 / 18

Doc.-no.: DPC200-MOD_02_EN Issue: 08/2019
14
Communication baud rate:
The communication baud rate indicates the transmission rate in bits per second. It must
be the same throughout the Modbus network.
Parity check:
The parity check is a method for error detection in binary coded data. With this method a
parity bit is sent with each byte which contains the information of modulo two. The parity
setting must be the same throughout the network.
The DPC200-MOD supports the following parity modes:
none No parity check is performed and no additional parity bit is sent.
even
The parity bit is / must be HIGH, if the preceding byte modulo 2 is
equal to zero.
odd
The parity bit is / must be HIGH, if the preceding byte modulo 2 is
equal to one.
none 2 stop bits
No parity check is made, instead of the parity bit another stop bit
is sent. This mode is suitable for heavily disturbed connections.
Telegram structure:
A send telegram always consists of two bytes and three words.
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit
ID FC DA DA D D CRC CRC
8bit 8bit 16bit 16bit 16bit
The telegram is transmitted byte wise, only in the Modbus context, some bytes are
regarded as words.
Function code
The device supports three function codes: 0x03 = read holding register
0x04
= read input registers
0x06 = write single register
ID = Modbus adress FC = function code DA = data address D = data CRC = checksum
Menu features:
The DPC200-MOD menu has been extended by four more points.
1)
modbus
ON / OFF
Modbus func-
tion on and off
3)
modbus baud rate
7200 / 9600 / 14400 /
19200 / 38400 / 57600
communication
baud rate
2)
modbus address
1 - 247
device adress /
device ID
4)
modbus parity
none / even / odd /
none 2 stop bits
parity check
Byte = 8bit 11111111 (U)SINT (Short-Integer)
Wort = 16bit 11111111 11111111 (U)INT (Integer)
OPERATION