Siemens SIMATIC ET 200S Operating Instructions Manual page 205

Isochronous mode
In isochronous mode, the 1Count5V accepts control bits and control values from the control
interface in each bus cycle and reports back the response in this mode in the same cycle or
in the next cycle.
In each cycle, the 1Count5V transfers the count or latch value that was valid at time T
the status bits valid at time T
A count controlled by hardware input signals can only be transferred in the same cycle if the
input signal occurred before time T
Technological Functions
Operating Instructions, 06/2010, A5E00124867-07
.
i
.
i
1Count5V
3.9 Position feedback
and
i
205