If allowed in par. K-40 [Hand] Button on Keypad, par. K-41 [Off] Button on Keypad, par. K-42 [Auto] Button on Keypad, and par. K-43 [Reset] Button on Keypad, it is

possible to start and stop the frequency converter bykeypad using the [Hand] and [Off] keys. Alarms can be reset via the [RESET] key. After pressing the [Hand]

key, the frequency converter goes into Hand Mode and follows (as default) the Local reference set by using the keypad arrow keys up [

After pressing the [Auto] key, the frequency converter goes into Auto mode

and follows (as default) the Remote reference. In this mode, it is possible to

control the frequency converter via the digital inputs and various serial in-

terfaces (RS-485, USB, or an optional network). See more about starting,

stopping, changing ramps and parameter set-ups etc. par. group O-5# (serial

communication).

Hand Off

Auto

keypad Keys

Hand

Hand -> Off

Auto

Auto -> Off

All keys

The table shows under which conditions either the Local Reference or the Remote Reference is active. One of them is always active, but both can not be active

at the same time.

Local reference will force the configuration mode to open loop, independent on the setting of par. H-40 Configuration Mode.

NB!

Local Reference will be restored at power-down.

2.8.4 Control Structure Closed Loop

The closed loop controller allows the drive to become an integral part of the controlled system. The drive receives a feedback signal from a sensor in the system.

It then compares this feedback to a set-point reference value and determines the error, if any, between these two signals. It then adjusts the speed of the motor

to correct this error.

For example, consider a pump application where the speed of a pump is to be controlled so that the static pressure in a pipe is constant. The desired static pressure

value is supplied to the drive as the set-point reference. A static pressure sensor measures the actual static pressure in the pipe and supplies this to the drive as

a feedback signal. If the feedback signal is greater than the set-point reference, the drive will slow down to reduce the pressure. In a similar way, if the pipe

pressure is lower than the set-point reference, the drive will automatically speed up to increase the pressure provided by the pump.

Reference Site

par. F-02 Operation Method

Linked to Hand / Auto

Local

Remote

AF-600 FP Design Guide

▲

] and down [

Active Reference

Local

Remote