Siemens SENTRON ATC6300 - Page 152

MODBUS communication
11.3 MODBUS ASCII protocol
3KC ATC6300 transfer control device
150 Manual, 03/2018, L1V30535632002A-01
Example:
In order, for example, to read the current voltage value of Line 1 between L3-L1 (0Ch) of a
slave using the serial address 08, the following message must be sent:
:
08
04
00
0B
00
02
E7
CRLF
: = ASCII 3Ah Message Start delimiter
08 = Address of the slave
04 = MODBUS function Read Input Register
00 0B = Address of the register (L3 voltage); reduced by 1
00 02 = Number of registers to be read, starting at Address 04
E7 = LRC Checksum
CRLF = ASCII 0Dh0Ah = Message end delimiter
The following reply is sent by the ATC6300:
: 08 04 04 00 00 01 90 9B CRLF
: = ASCII 3Ah Message Start delimiter
08 = ATC address (Slave 08)
04 = Function requested by the master
04 = Number of bytes sent by the multimeter
00 00 01 90 = Hexadecimal value of the voltage of Line 1 L3-L1 = 400 V
9B = LRC Checksum
CRLF = ASCII 0Dh0Ah = Message End delimiter