Siemens SINAMICS S120 - Page 824

Communication
11.3 Communication via PROFINET IO
Drive functions
824 Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Name
Limit value
Description
T
IO_Input
T_IO_InputMIN ≤
T_IO_Input < T_DC
Time of actual value acquisition
This is the time at which actual values are acquired before a new cycle
starts.
T
IO_Input
= T_IO_Input · T
IO_BASE
T_IO_Input: integer factor
T
IO_InputMIN
Minimum value for T
IO_Input
Calculation: T
IO_InputMIN
= T_IO_InputMIN · T
IO_BASE
= 375 µs
T
IO_Output
T_IO_Output_valid +
T_IO_OutputMIN ≤
T_IO_Output < T_DC
Time of setpoint transfer
This is the time, calculated from the beginning of the cycle, at which the
transferred setpoints (speed setpoint) are accepted by the closed-loop
control system.
T
IO_Output
= T_IO_Output · T
IO_BASE
T_IO_Output: integer factor
T
IO_OutputMIN
Minimum value for T
IO_Output
Calculation: T
IO_OutputMIN
= T_IO_OutputMIN · T
IO_BASE
= 250 µs
T_IO_Output_valid The time after which the new control output data (setpoints) is available
for the drive object.
Dx Data_Exchange
This service is used to implement user data exchange between the IO
controller and IO device 1 - n.
R or Rx
Computation time, current or position controller
Setting criteria for times
● Cycle (T
DC
)
– T
DC
must be set to the same value for all bus nodes. T
DC
is a multiple of SendClock.
– T
DC
> T
CA_Valid
and T
DC
≧ T
IO_Output
T
DC
is thus large enough to enable communication with all bus nodes.
● T
IO_Input
and T
IO_Output
– Setting the times in T
IO_Input
and T
IO_Output
to be as short as possible reduces the dead
time in the position control loop.
– T
IO_Output
> T
CA_Valid
+ T
IO_Output_MIN
● Settings and tuning can be done via a tool (e.g. HW Config in SIMATIC S7).