Re: Information on using SYNC
Uwe Koppe <[email protected]>
| Newsgroups | gmane.comp.hardware.bus.can |
|---|---|
| Organization | MicroControl GmbH & Co. KG |
| Message-ID | <[email protected]> |
Hello Jeff, you find a detailed explanation of the SYNC service in the CiA 301 document: http://www.can-cia.org/index.php?id=specifications&no_cache=1 For the SYNC service you need to calculate the bus load, which is caused by the SYNC message. Assuming that each PDO has 8 bytes and you run the bus at 125 kBit/s, this will lead to 130 * 8 us = 1,04 ms for each CAN message. This means 40 slaves nodes, having each 1 TPDO, will require 41,6 ms for the response of the SYNC message. Sending a SYNC telegram every 42 ms will result in a 100 % bus load then (which is not recommended when you want to have other CANopen services). If you send the SYNC message faster than the calculated 42 ms, then you won't receive the answers of nodes with lower priority identifiers. Best regards, Uwe ------------------------------------------------------------------------- MicroControl GmbH & Co. KG www.microcontrol.net ------------------------------------------------------------------------- -- Archives and useful links: http://groups.yahoo.com/group/CANbus Subscribe and unsubscribe at www.vector.com/canlist/ Report any problems to <[email protected]>