Repeaters are necessary when the distance between sender and receiver is too large to establish an adequate radio connection. Then the repeater will be placed in a distance where both, sender and receiver have a good connection to the repeater. The job of the repeater is to receive the telegram from the sender and send it again, so that the target receiver can get it.

Note:: More information about the Repeater you can find in EnOcean Radio Protocol.pdf, References.

A repeated telegram is not repeated again by any repeater. With this feature the maturity time of received telegrams is ensured.

The repeater always repeats sending 3 subtelegrams independently of the amount of received subtelegrams. All original and repeated subtelegrams must arrive within 100ms for the receiver to consider them as part of the same telegram. When this condition is fulfilled original and repeated subtelegrams belonging to the same telegram are saved by the receiver in one SW buffer. Thus they appear only as 1 radio telegram to the receiver application.

Note:

If you want that a telegram sent from your application is not repeated, set the telegram repeater counter to 0xF.

If a repeater receives original and repeated subtelegrams, the repeater counter of the 1st subtelegrams defines if the telegram is repeated again or not. The same behavior has the API interface. When calling radio_getTelegram you always receive repeater counter of the first subtelegram, even if several subtelegrams from repeaters has been received.

When you enable the repeater functionality in the API using the rep module the API will repeat every telegram without the help of to the application. The scheduler manages the repeat process. If you wanted to indicate for instance with a LED on your module that a telegram has been repeated do the following:

switch on the repeater
check the status of the telegram received by radio_getTelegram2
check the repeater counter of the telegram. If repeater counter > 0, set the LED