Can Bus Sampling Time - Siemens Sinamics S120 Commissioning Manual

Add infeed

2.10 CAN bus sampling time

2.10 CAN bus sampling time
The sampling time of the CBC10 can be set with the parameter p8848 "IF2 PZD sampling
time".
In the factory setting, the sampling time is 4 ms. Asynchronous message frames can be
received and sent within a period of 4 ms.
Cycle time
● For cyclic receive message frames, the cycle time, according to the Shannon sampling
theorem, must be greater than twice the sampling time. If the cycle time is long enough,
no receive message frame is lost and alarm A08751 is not output.
Example: The SYNC cycle should be 3 ms. The setting in p8848 =1 ms. So the cycle time
is larger than double the sampling time.
● For receive message frames, whose data does not change according to the Shannon
sampling theorem faster than twice the sampling time, then the cycle time can be
increased. Alarm A08751, which is output when the cycle time is increased, can be
suppressed by changing over the message type to "No message" using parameters
p2118, p2119.
Setting the CAN bus sampling time using p8848:
● Set the device commissioning parameter filter p0009 = 3 (drive basis configuration).
● Change and save parameter p8848.
● Set parameter p0009 = 0. The CU is automatically booted, and the parameter change
p8848 becomes effective.
78
Commissioning Manual, 11/2017, 6SL3097-4AA00-0BP3
CANopen interface