Kendrion Kuhnke Automation GmbH
Mix 02
111
17 May 2021
synchronised with DC (DC=Distributed Clocks)
Analogue Inputs / Oversampling Synchronised with SM
The module measures 4 analogue values per millisecond and adds or does not add them to the process
image, depending on what the Oversampling parameter (Object Index 0x2000) is set to. The default is 5.
This setting refreshes the analogue process image every 5 ms (check how counter input
SampleCycleCounter
increments). The readings taken every millisecond are entered in
Sample0..4
of
variable
AnalogIn0.. AnalogIn4
.
Lower parameter settings refresh the process image more often and the unused sample values are left
blank.
Example:
Oversampling parameter = 1 refreshes the process image after 1 millisecond already.
Values will be entered in
Sample0
only.
Sample 1..4
are left blank.
Oversampling Synchronised with DC
Interrupt SYNC0 is used for analogue sampling whereas interrupt SYNC1 is used to transfer the data to the
process image.
SYNC0 can be 1 to 5 times faster than SYNC1.
Example 1:
Bus cycle = 5 ms. Setting to use: "DC-synchronised 5x oversampling".
This is running Sync1 every 5 ms and SYNC0 every 1 ms.
Thus, analogue samples are read every millisecond and added to
Sample 0 to 4
of the process image after 5
ms. The
SampleCycleCounter
increments after 5 ms.
Example 2:
Bus cycle = 2 ms. Setting to use: "DC-synchronised 4x oversampling".
This is running Sync1 every 2 ms and SYNC0 every 0.5 ms.
Thus, analogue samples are read every half millisecond and added to Sample 0 to 3 of the process image
after 2 ms. Sample4 stays 0. The SampleCycleCounter increments after 2 ms.
Example 3:
Bus cycle = 1 ms. Setting to use: "DC-synchronised".
This is running Sync0 every 1 ms.