Rev 03/2022
V1.0 - Page
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Subject to modifications!
romutec Steuer.-und Regelsysteme GmbH Jochsberger Straße 39 D-91592 Buch am Wald
Subject to technical changes
4 Configuration
4.1 Hardware
Maximum number of expansion modules per Modbus interface
Basically, as many modbus devices can be connected to a bus interface as addresses can be set. The
complete address range of 0 ... 254 is available, but only the adresses 1..247 are for legal-use. The
adresses 248 until 254 are reserved in Modbus p
rotocol. However, please adhere to the DDC’s
manufacturer's recommendations concerning the maximum number of slave devices which may be
connected to the bus interface of the master device, as well as any constraints given for the address
range.
Basically, on the bridge you can connect up to 192 devices on the isolated serial 1 side and 63
devices on the non isolated serial 2 side without a Repeater.
Address 0 is reserved for multicast, the addresses 248 to 254 are reserved for bridge and similar
infrastructure functions.
Installation and wiring
Installation and wiring of the module will be done in the cabinet on the mounting plate.
Addressing Serial Interface
All incoming Modbus TCP requests are sent out on both serial interfaces. So you have to ensure that
the address of every slave device is unique over both interfaces.
Addressing TCP/IP Interface
The address of the TCP/IP interface can be set in the web interface.
You have two options:
•
DHCP
•
Static IP address
If you choose the option DHCP, the bridge is given an IP address from an available DHCP-Server.
If you have set a static IP instead, the bridge will work with these settings on TCP/IP.
Except of your settings, the bridge is available any time on AP mode by starting the web interface
calling the URL http://192.168.10.1. In AP mode your management device will take an IP given from
bridge (DHCP), which usually is 192.168.10.2.
