User Manual Instruction Manual

Application Notes 13-55
The deadband, as it relates to the analog input, can be calculated as follows:
1. The ratio of analog input volts to frequency (Volts/Hertz) needs to be calculated.
The voltage span on the analog input is 10 volts. The frequency span is 60 Hz.
2. Determine the frequency span between the minimum and maximum speed limits
and the Speed Ref A Hi and Lo.
3. Multiply by the volts/hertz ratio
Here, the deadband is “shifted” due to the 50 Hz limitation. The command frequency
from 0 to 3 volts on the analog input will be 15 Hz. After 3 volts, the frequency will
increase at a rate of 0.2 volts per hertz up to 9 volts. After 9 volts on the analog input
the frequency command will remain at 45 Hz.
13.20 Analog Outputs
13.20.1 Explanation
Each GV6000 has two analog outputs that can be used to annunciate a wide variety of
drive operating conditions and values.
The user selcts the analog output source by setting Analog Out1 Sel (342) or Analog
Out2 Sel (345). See Chapter 11 for a list of potential selections.
13.20.2 Absolute (default)
Certain quantities used to drive the analog output are signed, i.e. the quantity can be
both positive and negative. The user has the option of having the absolute value
(value without sign) of these quantities taken before the scaling occurs. Absolute value
is enabled separately for each analog output via the bitmapped parameter Anlg Out
Absolut (341).
Important: Important: If absolute value is enabled but the quantity selected for output
is not a signed quantity, then the absolute value operation will have no
effect.
13.20.3 Scaling Blocks
The user defines the scaling for the analog output by entering analog output voltages
into two parameters, Analog Outx Lo and Analog Outx Hi. These two output voltages
correspond to the bottom and top of the possible range covered by the quantity being
output. The output voltage will vary linearly with the quantity being output. The analog
output voltage will not go outside the range defined by Analog Outx Lo and Analog
Outx Hi.
10 Volts/50 Hz = 0.2 Volts/Hz
Speed Ref A Hi (91) – Maximum Speed (82) = 50 – 45 = 5 Hz
and . . .
Minimum Speed (81) – Speed Ref A Lo (92) = 15 – 0 = 15 Hz
5 Hz x 0.2 Volts/Hz = 1 Volt
15 Hz x 0.2 Volts/Hz = 3 Volts