Instruction manual

49
6
NETWORK VARIABLES
6.4.2 Speed adjustment (0.005% increments) (network input
SNVT_lev_percent nviDrvSpeedScale)
You can set the set frequency in 0.005% increments on the assumption that the frequency set in "reference
frequency setting (nciNmiFreq)" (Refer to page 101) is 100%.
⋅ When the state of nviDrvSpeedStpt is H1, the motor is placed in forward rotation status if nviDrvSpeed
Scale value is positive and placed in reverse rotation status if the value is negative.
⋅ When state of nviDrvSpeedStpt is H0, the motor is at a stop status.
⋅ Data acceptance timing........... At network variable receive (nv_update_occurs event)
The frequency to be written to the inverter actually is as shown in the following formula.
For example, when "Reference frequency setting (nciNmlFreq)" = 60.0Hz, "Speed adjustment
(nviDrvSpeedScale)" = -150%, and "Simple speed setting (nviDrvSpeed Stpt.value)" = 50%, output
frequency is (60.00Hz × ( -150%) × 50%) = -45Hz.
Therefore, a reverse command of 45Hz is given.
Data Name Initial Value Range Increments
nviDrvSpeedScale
100.00% (NciDrvSpeedScale value)
(Refer to page 101)
-163.840% to 163.830% 0.005%/bit
Set frequency = | (reference frequency setting × speed adjustment × simple speed setting)|
REMARKS
• The variable is initialized to "100.00%" at power-on or if it is not updated within the set "heartbeat receive time
interval (nciRcvHrtBt)" (Refer to page 97).
• Control can not be exercised at less than the minimum frequency resolution (0.01Hz) of the inverter.
• To make the change of "reference frequency setting (nciNmlFreq)" reflected to the operation speed, a value is need
to be written to speed adjustment (nviDrvSpeedScale)