Table 11: description of transmission type – Applied Motion ST10-C-CE User Manual

Page 31

Advertising
background image

31

920-0025 Rev K

3/5/2015

CANopen User Manual

The PDO valid/not valid bit allows for the selection of which PDOs are used in the opera-

tional state. There may be PDOs fully configured (e.g. by default) but not used, and therefore

set to “not valid” (deleted). The feature is necessary for devices supporting more than 4 RP-

DOs or 4 TPDOs, because each device has only default identifiers for the first four RPDOs/TP-

DOs. Devices supporting the standard CAN frame type only or not supporting Remote Frames,

an attempt to set bit 29 to 1 or bit 30 to 0 will be met with an abort message (abort code: 0609

0030h). Changing bit 0-29 is not allowed while the PDO exists (Bit 31=0).

The transmission type (sub-index 2) defines the transmission/reception character of the

PDO. Table 11 describes the usage of this entry. On an attempt to change the value of the

transmission type to a value that is not supported by the device an abort message (abort code:

0609 0030h) is generated.

transmission type PDO transmission

cyclic

acyclic

synchronous

asynchronous

RTR only

0

X

X

1-240

X

X

241-251

- reserved -

252

X

X

253

X

X

254

X

255

X

Table 11: Description of transmission type

Synchronous (transmission types 0-240 and 252) means that the transmission of the

PDO shall be related to the SYNC object. Preferably the devices use the SYNC as a trigger

to output or actuate based on the previous synchronous Receive PDO respectively to update

the data transmitted at the following synchronous Transmit PDO. Details of this mechanism

depend on the device type and are defined in the device profile if applicable.

Asynchronous means that the transmission of the PDO is not related to the SYNC object.

A transmission type of zero means that the message shall be transmitted synchronously

with the SYNC object but not periodically. A value between 1 and 240 means that the PDO is

transferred synchronously and cyclically. The transmission type indicating the number of SYNC

which are necessary to trigger PDO transmissions.

Receive PDOs are always triggered by the following SYNC upon reception of data inde-

pendent of the transmission types 0 - 240. The transmission types 252 and 253 mean that the

PDO is only transmitted on remote transmission request. At transmission type 252, the data is

updated (but not sent) immediately after reception of the SYNC object.

At transmission type 253 the data is updated at the reception of the remote transmission

request (hardware and software restrictions may apply). These value are only possible for

TPDOs.

For TPDOs transmission type 254 means, the application event is manufacturer specific

(manufacturer specific part of the Object Dictionary), transmission type 255 means, the

application event is defined in the device profile. RPDOs with that type trigger the update of the

mapped data with the reception.

Advertising