VFD - Configuring 2 frequency sources
Ofir Levi
Jul-12th, 2018 11:42

There are 2 frequency sources that can be configured for the VFD – A and B.

P00.06 – frequency source A

P00.07 – frequency source B

There are 2 ways to select which source will be active:

1.       Via P00.09 (Combination of the setting source)

2.       Via digital input (S1,S2,Sx…) One of the methods to change the source frequency (A & B) can be via digital input.

Setting the value 13 (Shift between A setting and B setting) to one of the digital inputs configuration (terminal function selection) in P05.01 – P05.08 will determine the source of the Frequency according to the input state.


One wishes to have a backup for his frequency source. The normal configuration for the frequency source is analog input and the backup will be constant speed.

In this case he can configure Frequency Source A to Analog input 2 and Frequency Source B to multi step speed.

One of the digital inputs can be configured to switch between the frequency sources. 


Set P00.01 (Run command channel) to 1 (Terminal running command)

Set P00.06 (A frequency command selection) to 2 (Analog AI2)

Set P00.07 (B frequency command selection) to 6 (Multi step speed setting).

Set P05.01 S1 to 1 (Forward operation)

Set P05.02 S2 to 16 (Multi step speed terminal 1) 

* Please note that step of the multi speed configuration will be determined by the bitmap table (see below).

   in this case if S2 (terminal 1) is on the speed is determined by 10.04

Set P05.03 S3 to 13 (Shift between A setting and setting)

Set P10.04 (Multi step speed 1) to the required speed (100% will be parallel to max frequency). 0-100%

Example Operation:

When S1 will be enabled the motor will run forward according to the frequency in AI2.

In order to switch between frequency source – Stop the VFD  (turn off S1).

Enable S2 and S3 , the motor source  frequency will be changed to Multi step speed 1 (P10.04)

Enable S1 the motor run forward to according to value in P10.04.

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