Lenze EMF2179IB - Manual (Page 60)

EMF2179IB communication module (DeviceNet)
Data transfer
5
5.6
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5.6-1 EDSDEN EN 02/2006
5.6 Data transfer
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Note!
When using the DeviceNet communication profile, the
corresponding specified terminology must be considered. Note
that translation into German is not always permissible.
In these instructions, the following terms are used with the
same meaning:
ƒ I/O data ↔Process data
– Input data is process data to the scanner
– Output data is process data from the scanner
ƒ Explicit Messages ↔Parameter data
ƒ Scanner ↔ DeviceNet master
Between the master computer and the controller(s), the ”I/O data” and
”Explicit Messages” telegram types are transmitted.
ƒ I/O data
I/O data (process data) is transmitted or received according to the
producer/consumer principle, i. e. there is one transmitter and no or an
arbitrary number of receivers.
The following transmission modes are supported:
– I/O polled messages (polled): the poll command sent by the master
includes output data for the slave. The slave then sends its input data
to the master. The poll response can also be used to confirm the
received data.
– Cyclic I/O: by means of cyclic I/O, master and slave create data
independently of each other which is sent according to the settings of
a timer. The user must set the timer.
– This type of I/O message is a special cyclic message. COS nodes send
their data when the data status is changed.
ƒ Explicit messages
Explicit messages are used for configurationand parameter setting of the
devices connected to the DeviceNet. The relationship between two
devicesisaclient-serverrelationship.Theclientsends therequest andthe
server accepts the order and tries to carry it out. The server reacts as
follows
– the required data in case of a positive response or
– a fault message in case of a negative response.
The target address and the service (request <-> response) are data coded.
Telegram types