Specifications

The 5th byte from the incoming message from SCADA centre is used to replace the last byte of the

Base IP and the resulting IP address is used as the destination of the UDP datagram which contains

the original SCADA message.

Let assume that the content of 5th byte is 0x65 - then the IP destination address will be 10.0.0.101 and

the UDP port 8882.

The translation by a table is more versatile, however it requires an extra line of configuration for every

remote in the network. The table has to be used when addresses of RipEX radiomodems and SCADA

RTUs do not match or different ports (interfaces) at different remotes have to be configured.

The example of table in the picture above demonstrates a situation when there are three SCADA

devices connected to the COM2 of a single RipEX unit over a RS485 bus.

The configuration of a Slave radiomodem is very simple, as demonstrated in the picture below. When

a UNI Slave receives the UDP datagram from RF channel, it takes the original SCADA message and

transmits it over the respective interface (the COM2 in our example).

If the SCADA device connected responds to the message within a timeout of 500 ms, the source IP

address of the received UDP datagram is used as the destination for the response.(Note only one

packet is accepted as a response). When the timeout expires, all messages received by the serial in-

terface are discarded.

UNI protocol