Watlow 8LS Controller Manuale Utente Scaricare il pdf (Pagina 85)

Tuning and Control

8LS User’s Guide 77

However, a process which uses only Proportional control may settle at a

point above or below the setpoint; it may never reach the setpoint at all.

This behavior is known as “offset” or “droop”. (This diagram shows a

process under proportional control only.)

Proportional and Integral Control

For Proportional and Integral control, use the Integral term, or Reset,

with Proportional control. The Integral term corrects for offset by

repeating the Proportional band's error correction until there is no error.

For example, if a process tends to settle about 5

F below the setpoint,

use Integral control to bring it to the desired setting. (The next diagram

shows a process under proportional and integral control.)

1 2 ... 80 81 82 83 84 85 86 87 88 89 90 ... 139 140

Nessun commento

Watlow 8LS Controller Manuale Utente Pagina 85