Lenze PROFIBU PC-based Automation Instrukcja Użytkownika Pobierz pdf (Strona 57)

DMS 2.2 EN 07/2011 TD17 L 57

Control technology | PROFIBUS communication manual

Defining the minimum cycle time of the PLC project

Calculating the total access time to the peripheral devices (T

Correction

)

9 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 comprises 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

) ( 57)

2. Determining the task utilisation T

Task utilisation

of the application during operation.

Detecting the task utilisation of the application (T

Task utilisation

) ( 58)

3. Calculating the minimum cycle time.

Calculating the minimum cycle time

( 60)

4. Optimising the system.

Optimising the system

( 61)

9.1 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

1 PROFIBUS master (logic) 140 μs

1. axis

(16 input words and 16 output words)

40 μs

For each further axis

(16 input words and 16 output words)

10 μs

Access times for an industrial PC (ATOM 1.6 GHz) with 3 axes

Access time of PROFIBUS master

+ access time of 1. axis

+ access time for 2 further axes

140 μs

40 μs

20 μs

= total access time 200 μs

1 2 ... 52 53 54 55 56 57 58 59 60 61 62 ... 68 69

Komentarze do niniejszej Instrukcji

Brak uwag

Lenze PROFIBU PC-based Automation Instrukcja Użytkownika Strona 57

Komentarze do niniejszej Instrukcji

Powiązane produkty i podręczniki dla Sprzęt komputerowy Lenze PROFIBU PC-based Automation