Title: +038=360.012-#####._06-BA-ESR NI-DV Controller Nicotra Gebhardt - Operating Instruction.pdf
Other functions, such as alarm read-out and acknowledgement, are still possible via Modbus even though "Modbus control" is not activated. • NOTE! Contact Nicotra Gebhardt GmbH if you require the Modbus protocol.5.3. Switching frequencySwitching frequency is crucial in determining the amount of audible acoustic noise emitted by OJDV. The higher the switching frequency, the less audible noise will be emitted by NI-DV. At the same time, however, internal losses will be increased, reducing efficiency. NI-DV can be set to operate constantly with a switching frequency of either 4 kHz or 8 kHz, or it can be set to change switching frequency automatically depending on motor speed (AUTO setting). Switching frequency (switching mode) is set via Modbus: • Setting ”4kHz” = Constant 4kHz switching frequency • Setting ”8kHz” = Constant 8kHz switching frequencySetting ”AUTO” = Switching frequency is changed automatically: o At motor speeds higher than 60% of rated speed, switchingfrequency is changed to 4 kHz