User Manual
1. System summary
1−19
Festo GDCP−SFC−LACI−DN−EN en 0812NH
I/O Messages
(I/O Messaging)
I/O messages are sent by a station, and can be received and
processed by one or more stations. For I/O messages, the
following
dialogues are possible between the stations:
the slaves are interrogated cyclically by the master
(Polled I/O), or
the messages are sent either by the
master or by the
slave cyclically, or when there is a change of state
(COS/Cyclic), or
all slaves are scanned by the master with a command
(Bit Stro
be" is not supported by the SFC−LACI).
The data field contains exclusively user data; no protocol
data are specified. All information on using the data are
save
d in the assigned Connection Object".
Up to 64 field bus nodes can be operated via the serial
CANbus in a DeviceNet network. The extent
of the network
depends on the baud rate selected (125 kBaud, 250 kBaud or
500 kBaud).
DeviceNet telegrams contain up to 8 bytes of user data. If it is
necessary to
exchange larger amounts of data, then the data
are broken down by means of fragmentation before being
sent, transmitted sequentially and then put togethe
r again in
the recipient. This normally occurs automatically.
The configuration data contain the source and the destina
tion address of the data for the sende
r and recipient of the
messages.