User's Manual

ManualsBrandsWürth Elektronik ManualsElectronicsDigital transmission module

Please note that the RF settings (e.g. RF proﬁle, RF channel, address mode,

repeater settings) must be the same for all nodes in the network.

Violation may cause interrupted transmission, or received packets that cannot

to be interpreted correctly. In addition, the timing parameters in case of re-

peater or enabled ACKs must be the same for all nodes in a network.

The address mode 3 (254 network ids and 65534 addresses) is only supported

by the Tarvos-II and Tarvos-III.

Radio messages of devices that are using the same radio channel may inter-

fere with each other leading to possible collisions and packet loss.

5.2.2 Unicast

A module can use the command

CMD_DATA_REQ

to send data to a pre-deﬁned destination

speciﬁed by the parameters

MAC_DefaultDestAddr

and

MAC_DefaultDestNetID

. Besides

this, the command

CMD_DATAEX_REQ

triggers the data transmission to the address speciﬁed

in the command.

5.2.3 Multicast/Broadcast

The destination address or destination network id of 0xFF (255) or 0xFFFF (65535) stands

for a broadcast which will trigger any compatible receiver to interpret this frame to forward it

to its host.

5.2.4 Acknowledgement and retries

In order to improve reliability in communication, the module can be conﬁgured to use radio

acknowledgement and retry mechanism. It can be activated using the parameter

MAC_NumRetrys

accordingly and only in case of non-broadcast messages.

5.2.5 Packet sniffer mode

The address resolution can be disabled ("packet sniffer") by enabling the sniffer mode in the

UserSetting

CfgFlags

. A module in sniffer mode will accept all data packets (ignoring the

target address) and forward them to the serial interface. Furthermore, it does not send any

acknowledgement and cannot work as repeater at the same time (see section

5.2.6 Repeater mode and mesh network

The module can be run as a repeater to artiﬁcially extend the range of sending devices in an

existing network. A module conﬁgured as repeater, simply re-transmits the received packet

after a random back off time. This mode allows options to build a

flooding mesh

network

described in detail in chapter

5.3 System conﬁguration parameters

The parameters that determine the functionality of the module are classiﬁed into two cate-

gories. The non-volatile UserSettings (see chapter

) values that can be modiﬁed using the

CMD_SET_REQ

command retain their values after a power reset.