KROHNE Summit 8800 Vol 3 - Manual (Page 131)

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08/2013 - MA SUMMIT 8800 Vol3 R02 en
SUMMIT 8800 COMMUNICATION 08
Timeout Time to stop connectivity attempts between the devices
Retries Number of attempts to establish communication before an alarm is given
Modbus ID Unique identifier for the Modbus device
The Modbus slave is defined in a file “redundancy slave” which can be imported as a modbus
list.
8 .3 .8 Custom Modbus master
Modbus master drivers are created as a programming script. The script programming language
is LUA, which allows drivers to be programmed or modified. Further details of this custom pro-
gramming can be found in the LUA chapter.
Within master type there is a custom option, which opens such script page.
Figure 177 LUA script page
To modify an existing modbus master driver, first select the driver to be modified, then open the
custom master. After the changes are made, the driver can be exported and imported to be used
in other applications.
8 .4 Modbus slave
Select Modbus slave, should the SUMMIT 8800 be the slave device and the field device is the
master - where the SUMMIT 8800 is sending data every time it is polled by the master device.
In the Summit the modbus slave is used to allow other devices, such as SCADA systems, to get
information from the Summit. Traditionally a serial port is used for Modbus, but nowadays Mod-
bus over TCP/IP becomes more popular, so the Summit also supports this on its ethernet ports
where each Ethrnet port has 4 modbus slave links available.