UDP transmission of serial buses over LAN

In large alarm systems, it is quite often necessary to extend the RS485/422 serial buses over the LAN. For this purpose, we have developed managed industrial LAN-RING switches, miniLAN and LAN-485 converters equipped with RS485/RS422/RS232 serial interfaces.

The main advantage of UDP communication is the ability to communicate with multiple counterparties. A typical application is the connection of control panels with system modules, readers and keypads. The metallic RS485 or RS422 bus is replaced by a "virtual" bus shared over UTP or optical fiber with other systems. However, due to the sensitivity of security systems to delays and proper fragmentation, optimization of the conversion to and from the UDP protocol is necessary for reliable communication.For this reason, we carefully test each system and, if necessary, modify the methods of fragmenting data into datagrams, implement communication protocol commands, etc.

All necessary settings are divided into two simple menus.

Setting up multicast addresses

Data from the serial buses are transmitted bidirectionally via multicast addresses. One of the advantages of this communication is the possibility of connecting many points without multiplying the data flow due to the establishment of separate connections (TCP). That is, even with 100 end points (modules) there is only one stream.

Communication protocol settings

The following options are used for UDP:

• RS485 - suitable for ATS, Ronyo etc.
• Dominus - optimized for Domius
• Galaxy - optimised for Galaxy
• Peridect - optimised for Peridect
• Cias - optimised for Cias

Example of EZS connection and configuration