SPEEDMASTER Inverter - Speed Motor Problem

[2X]

Hello,
I have a SPEEDMASTER Inverter "SM SERIES SUB-MICRO INVERTERS". I put another "Electronic Programming Module (EPM)" from a unit that didn't work to test the EPM module and then my good inverter shown in the display the code "cF". So according to the manual I made a factory reset (Parameter: 48 - RANGE OF ADJUSTMENT: 04). The motor that is connected to the inverter is controlled via a PCB where takes commands from a PC. The problem after the reset is that whatever speed if I select on the program the motor always run with the same exactly speed and the inverter shows always (independently of whatever speed is selected on the PC) 20.0 (I believe this is the output hertz. I changed the “parameter 27” but the same again (my power supply is 230V/50Hz).
Do you know what parameter I have to change in order the frequency output of the inverter not to be constantly at 20Hz?

[2X]

One weird thing. I copy all the settings from an inverter that is in a similar machine and doesn't work again except If I touch the oscilloscope probe on the pins of an optocoupler the motor start works flawlessly in whatever speed I will set for the PC program but if I stop the motor then doesn't start again except If I touch it again with the oscilloscope probe on the pins of the optocoupler.

I have the same inverter on another same machine but the password of the invert isn't the factory, so I can't copy the settings. Do you know if I try one by one all the numbers until, I will find the right password the inverter has limit on the tries of wrong password that I can insert and then will lock (like smartphones)? I didn’t read something in his manual (page 41).

[m k]

Are you sure something else is not controlling that speed, or that you actually changed the speed?

Getting an effect with scope probe indicates that touched input is floating.

[2X]

Are you sure something else is not controlling that speed, or that you actually changed the speed?

Getting an effect with scope probe indicates that touched input is floating.

Hello, I am sure because the other machine is the same and works fine. Do you know something about the password tries?

[m k]

No.
From where you got that wrong password is locking the device?

P27 is base frequency, V/Hz ratio.
What other settings you have changed from the default?
Default speed selection is buttons.

How PC is connected to inverter?