Avtron ADDvantage-32, Manual

Page: 117 / 290

Control Block Description
ADDvantage-32
4-55
4.38 IIT
1. Inputs
IA Analog
STPT Analog
IGN Analog
FST Analog
WST Analog
SQU Bit
ZER Bit
IRES Bit
2. Outputs
VAL
Analog
TRP Bit
WRN Bit
3. Implementation
The IIT block is used to determine the current overload for a motor. It can be used when
more than one motor is used with the drive.
When IRES is high, the integrator is reset to zero (VAL = 0).
When IRES is low, the integrator starts integrating the error.
If ZER is low, then the internal error signal is equal to absolute value of INP minus the
STPT input quantity times 0.1.
If ZER is HIGH, the error is equal to -(STPT) × 0.1.
This error is fed into the integrator if the SQU input bit is low, giving an IIT function.
If the SQU input is high, then this error is squared (the sign of signal is kept after the
squaring) before it goes into the integrator.
The integrator works the same as the PI block with the IGN input as its gain value and
VAL as its output.
FST is the upper limit of the integrator output and 0 is the lower limit.
When VAL goes above the WST input, the WRN output bit will go high.
When VAL goes above the FST input, the TRP output bit will go high.