Clocked Mode - Siemens SIMATIC ET 200S Operating Instructions Manual

3.2

Clocked Mode

Note
The principles of isochrone mode are described in a separate manual.
Hardware Requirements
You will require the following for the 1Count5V/500kHz in isochrone mode:
• A CPU that supports isochrone mode
• A master that supports the equidistant bus cycle
• An IM 151 that supports isochrone mode
Features
Depending on the system parameter assignment, the 1Count5V/500kHz works in either non-
isochrone or isochrone mode.
In isochrone mode, data exchange between the master and 1Count5V/500kHz is
isochronous to the bus cycle (PROFIBUS-DP/PROFINET).
In isochrone mode, all 8 bytes/12 bytes of the feedback interface are consistent.
If an error occurs during parameter assignment, the 1Count5V/500kHz does not go into
isochronous mode.
If isochrone mode fails due to faults or failure/delay of global control (GC), the
1Count5V/500kHz will return to isochrone mode during the next cycle without an error
response.
If isochronous mode fails, the feedback interface is not updated.
The T
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
/T overlap is supported by the module in firmware version V1.0.1 and later.
i o
1Count5V/500kHz
3.2 Clocked Mode
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