Lenze CANopen control technology - Manual (Page 87)

DMS 4.2 EN 07/2011 TD17
L
87
Control technology | CANopen communication manual
Defining the minimum cycle time of the PLC project
Calculating the total access time to the peripheral devices (T
Correction
)
12 Defining the minimum cycle time of the PLC project
This chapter will inform you on how the minimum cycle time of the PLC project can be
defined.
The calculation of the minimum cycle time is divided into the following steps:
1. Calculating the total access time T
Correction
to the peripheral devices.
Calculating the total access time to the peripheral devices (T
Correction
)
( 87)
2. Detecting the task utilisation T
Task utilisation
of the application during operation.
Detecting the task utilisation of the application (T
Task utilisation
)
( 88)
3. Calculating the minimum cycle time.
Calculating the minimum cycle time
( 90)
4. Optimising the system.
Optimising the system
( 91)
12.1 Calculating the total access time to the peripheral devices (T
Correction
)
The cycle times depend on the number of configured field devices and the IPC hardware
used.
Example
Configuration Access time with processor
ATOM 1.6 GHz
CAN master (Logic) 80 μs
per axis (Motion) 60 μs
Access times Industrial PC (ATOM 1.6 GHz) with 9 Motion axes
Access time CAN master
+ access time 9 Motion axes
80 μs
540 μs
= total access time 620 μs