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EK280
Application Manual
176
Short
Desc.
Description
Address Value
Content
MBTrM
Transfer mode
2:7B1
2
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
Info: "H-Byte first" has a fixed setting
MBAdr
Device address
(Modbus Slave ID)
2:7B2
1*
Value range from 1…247 (0 = "Broadcast")
MBRSz Register size
2:7B8
2
2: Register size 2Byte/16Bit
MBAMd Addressing mode
2:7B9
0
0: Log. Mode
Table 5: Preset Modbus parameter
* Value to be determined by the user.
The following connection parameters for connection 1 are set by default via parameter file (see paragraph a)
of this
chapter):
Short
Desc.
Description
Address Value
Content
Event
Connection event
1:D70
2F01
Call window1 created
EvTyp
Connection event type
1:D75
1
1: Period
Iface
Connection interface
1:D72
3
3: internal modem
SuplT
Connection power supply type
1:D76
2
2: Battery operation
TypPr
Connection protocol type
1:D77
0
0: Server (protocol detection)
IPInf
Additional information for the
connection
1:D79
0
0: no action
Table 6: Default connection parameters
i
For communication time window 1 (
, paragraph "d)") and the correct APN Data
(
, paragraph "c)") must be set.
8.2 Operating a Modbus Master
Modbus is a stateless single master protocol. Within the Modbus slave function of the EK280 (
the master (retrieval system) can only retrieve the data from the terminal (slave) during an open time
window. Opened time windows are always linked to increased energy consumption as the time window is
usually open for a longer period of time than what is required for communication and also during this time
e.g. the modem must be ready for reception.
With the Modbus master operation, this energy consumption can be reduced to the required minimum where
e.g. the modem is only switched on for the short period required for transmitting data. In such cases the
retrieval system takes over the role of the slave.
The Modbus master operation serves to send (time and/or) event-driven Modbus data (e.g. register or
archive data) to a slave, or to retrieve e.g. new configuration data or parameters from there.
The EK280 can communicate as a Modbus master by means of the terminal device (external modem) and
the internal modem in any transmission mode (ASCII, RTU, RTU-TCP).