Manual

CANopen Module Specification 23
Doc.Id. HMSI-216-117
CM CANopen Module for SIMATIC S7-1200
Doc.Rev. 1.00
RPDO Transmission Types
RPDOs can be received either in synchronous or asynchronous mode. A synchronization (SYNC) ob-
ject is transmitted periodically by a synchronization producer, located either in the CM CANopen Mod-
ule for SIMATIC S7-1200 or in another node on the CANopen network. The data in synchronous
RPDOs are not transferred to the SIMATIC S7-1200 PLC until after the next SYNC object is received.
Asynchronous RPDOs will be transferred to the SIMATIC S7-1200 PLC at reception.
The transmission type parameter of a RPDO specifies the triggering mode.
TPDO Transmission Types
TPDOs can be transmitted either in synchronous or asynchronous mode. A synchronization (SYNC)
object is transmitted periodically by a synchronization producer, located either in the CM CANopen
Module for SIMATIC S7-1200 or in another node on the CANopen network. Synchronous TPDOs are
transmitted within a pre-defined time-window immediately after a configured number of SYNC objects,
either always or after a CoS (Change of State event). Asynchronous TPDOs can be transmitted at any
time, triggered by a CoS or a cyclic period set in the Event Timer.
The transmission type parameter of a TPDO specifies the transmission mode as well as the triggering
mode.
6.3 Error Control
Different mechanisms exist to monitor the network. At an error event from any of these, the active I/O
data is frozen, as no new data will be available.
6.3.1 Heartbeat Mechanism
The Heartbeat Mechanism is used to monitor the nodes in the network and verify that the nodes are
available. A heartbeat producer periodically sends a message. The data part of the frame contains a byte
indicating the node status. The heartbeat consumer reads these messages. If a message fails to arrive
within a certain time limit (defined in the object directory of the devices, object 1016h,
page 27), a heart-
beat event is triggered by the consumer. The ERROR LED on the front of the CM CANopen Module
for SIMATIC S7-1200 will indicate the event and a diagnostic error will be logged to the SIMATIC S7-
Transmission
type, RPDO
Mode RPDO transmission description
0 - 240 Synchronous A received RPDO is transferred to the SIMATIC S7-1200 PLC after a SYNC object
is received.
241 - 253 - Reserved
254 - 255 Asynchronous,
Event driven
An RPDO is transferred to the SIMATIC S7-1200 PLC without any relation to the
SYNC object.
Note: All default PDOs are mapped with transmission type 255.
Transmission
type, TPDO
Mode TPDO transmission description
0 Synchronous,
acyclic
A TPDO is triggered by an event, but not transmitted before the occurrence of a
SYNC object
1 - 240 Synchronous,
cyclic
A TPDO is transmitted with every n-th SYNC object, where n is the defined number
from 1 - 240.
241 - 253 - Reserved
254 - 255 Asynchronous,
Event driven
A TPDO is transmitted without any relation to the SYNC object. The transmission is
triggered by a CoS event or if a specified time has elapsed without an event.
Note: All default PDOs are mapped with transmission type 255.