3 transmission type, Transmission type, 9system bus "can on board – Lenze 8400 BaseLine C User Manual
Page 190

9
System bus "CAN on board"
9.6
Process data transfer
190
Lenze · 8400 BaseLine C · Reference manual · DMS 1.6 EN · 01/2014 · TD05
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9.6.3
Transmission type
Process data objects can be transmitted in an event-controlled or time-controlled manner. The be-
low table shows that it is possible to combine the different methods by means of logic operations
(AND, OR):
• Event-controlled
The PDO is sent when a special device-internal event has occurred, e.g. when the data contents
of the TPDO have changed or when a transmission cycle time has elapsed
• Synchronous transmission
A TPDO (or RPDO) is transmitted (or received) after the device has received a sync telegram
(COB-ID 0x80).
• Cyclic transmission
The cyclic transmission of PDOs takes place when the transmission cycle time has elapsed.
• Polled via RTR
A TPDO is transmitted when another device requests it by means of a data request telegram
(RTR remote transmit request). For this purpose, the data requester (e.g. the master) sends the
data request telegram with the COB-ID of the TPDO requested to be sent. The receiver recogni-
ses the RTR and transmits the corresponding PDO.
Transmission type
PDO transmission
Logic combination of
different transmissi-
on types
cyclic
synchronous
event-controlled
0
AND
1 ... 240
-
254, 255
OR
Transmission type
Description
0
Synchronous and acyclic:
The PDO is transmitted on an event-controlled basis with every sync (e.g. when a bit change
occurs in the PDO).
1 ... 240
Synchronous and cyclic (sync-controlled with response):
• Selection n = 1: The PDO is transmitted with every sync.
• Selection 1 < n ≤ 240: The PDO is transmitted with every n-th sync.
241 ... 251
Reserved
252
Synchronous - only RTR
253
Asynchronous - only RTR
254, 255
Asynchronous - manufacturer-specific/device profile specific:
If this value is entered, the PDO transmission is event-controlled or cyclic.
(Note: The values "254" and "255" have the same meaning).
For a cyclic transmission, a cycle time must be entered for the respective PDO. In this case,
cyclic transmission takes place in addition to event-controlled transmission.