How to give frequency reference to the ATV312 drive in 0.01Hz increments with the communication.

it is possible with the high-resolution mode. We can change the precision of LFR (send by communication) to have high resolution.

To activate the high-resolution mode, the bit 9 of CMI (Modbus address- 8504) must be set to 1.

The LFR unit depends on the value of bit 9 of the extended control word (CMI):
1 = 0.1 Hz if bit 9 of CMI (page 20) = 0
1 ≈ 0.018 Hz (resolution 32767 points = 600 Hz) if bit 9 of CMI = 1
High resolution:  Standardized value at maximum frequency in 16 signed bits.

Note:
- The resolution can be changed only when motor is stopping
- The CMI parameter is not saved in EEPROM, so in case of power cycle on drive, you have to write the bit 9 to go in High resolution.

How it works:-
32767 = 600 Hz
LFR=>100=> the drive will run at 1.8 Hz
LFR=>1000 => the drive will run at 18.3 Hz
LFR=>2000=> the drive will run at 36.6 Hz
LFR=>2500=> the drive will run at 45.8 Hz
LFR=>2600=> the drive will run at 47.6 Hz

Released for: Schneider Electric India