Simple Frequency Converter

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This drive corresponds to a frequency controlled motor or a proportional valve. It has at least to be connected to one word (E, A-, M-, or data) of the PLC. Next to the address you have to specify as well at which value of the word the maximum speed shall be reached. If the word in the real PLC has to head for an analog output that shall specify a frequency converter +/- 10V you have to enter 27648 here.

 

Either you can specify the start and stop slopes or modify them by the PLC. The start slope will always be used if the drive is released (even if the speed is reduced). The stop slope will only be used if the drive is not released.

 

You can specify a release bit. If this bit is to be used the drive will only be released if it is active (exception: if the backward bit is to be used it will be enough if only that one is specified). The drive will run backward as well if a negative setpoint is specified.

 

Furthermore you can specify a backward bit. If this bit is specified the setpoint will be negated, that means by the help of this bit you can let the drive with only positive setpoint go backward and forward.

 

There are lots of frequency converters at the market and each is headed for in a little different way. We tried to design this drive so that it will be able to cope with as many demands as possible. Eventually you have to write some lines of codes in OB3 nevertheless to reach exactly the behaviour of the converter used by you.

 

This drive will also be used if none of the other drives seem to be appropriate, e.g. if you have got a motor with 3 speeds. Then you have to program the heading for the speed yourself, best in OB3.

 

The simple frequency converter gives also the possibility that a drive follows another one exactly. (Master slave operation). Therefore select the button ‘extended’. You can select the strange element on the edit mask that appears which shall be followed by the drive. You have to specify a freewheeling bit as well. If this bit is specified the drive will not follow its master but it will behave like a completely normal frequency converter. If your drive is never to be freewheeling you will have to specify a bit here that is ‘always 0’. Therefore we recommend the bit M 0.0 (and M 0.1 for ‘always 1’). Even a drive that is configured as slave has to be released so that it runs. That means either you activate the check box ‘use forward input’ or you will have to see to it that the specified bit is ‘1’ if the drive is to run.

 

The word motor is similar to the simple frequency converter but not that flexible. It still exists just because of reasons of compatibility and should not be used anymore if possible.

 

See also:

Other drives