
EK280
Application Manual
124
8.1.5
Modbus via RS232 interface
In the EK280 communication via the terminal interface in RS232 operation can be via Modbus amongst
others. Values can be read and updated and archives can be retrieved.
8.1.5.1 Connection
RS232 interface connection is described in chapters 7.4.1.1 and 7.4.1.2
8.1.5.2 Parametrization of the EK280
a) Parameterization of the functions of the RS232 interface is described in Chapter 7.4.1.3.
b) Send parameter file for Modbus parameterization
Send the following parameter file to the EK280. (see Chapter 3.6, page 17):
EK280_xvx. - RS232 & Modbus-RTU (via connection 5 & ext. power supply) (*)
21
c) For customized settings, the Modbus parameters can be set on the device under the path
"Admin" >
"Interfaces" > "Terminal interface" > "Modbus"
(see paragraph "d)").
i
All parameters listed on the EK280 "
Admin
" tab can be found in enSuite under "
Parameters
"
under the same path. To do this select "
Navigation
" on the left-hand side and then "
Parameterize
online
" at the bottom of the navigation window.
d) The following Modbus parameters are set by default via parameter file (see paragraph b) of this chapter):
Short
Desc.
Description
Address Value
Content
MBTrM
Transfer mode
2:7B1
1
0: ASCII - The content of each register is
transmitted as four ASCII-encoded hexadecimal
digits
1: RTU - The content of each register is
transmitted as two bytes
2: TCP - Transmission as for RTU mode with
additional information for Modbus TCP protocol
MBDir
Data direction
2:7B0
1
0: H word first
The most significant word is
located in the first register
1: L-Word first
The least significant word is
located in the first register
(the Byte order is always High Byte first).
MBAdr
Device address
(Modbus Slave ID)
2:7B2
1
22
Value range from 1…247 (0 = "Broadcast")
MBRSz
Register size
2:7B8
2
2: Register size 2Byte
4 Register size 4 Byte
The statement of the register size has a direct
influence on the possible register address in the
above Modbus table. Hence the setting of the
register size applies to both interfaces!
MBAMd
Addressing mode
2:7B9
0
0: Log. Mode (staring with "1")
1 Phys. Mode (staring with "0")
Table 2: Default Modbus parameter
21
The "x" stands for the version of software on the device, e.g. "2v2".
The star * stands for a small letter which indicates the version of the file, e.g. "a".
22
User-determined value