237-00156 SofTec Microsystems SRL, 237-00156 Datasheet - Page 77

• Manufacturer Part Number: 237-00156
• Description: BOARD ISOLATION FOR ST7
• Manufacturer: SofTec Microsystems SRL
• Type: Optoisolation Boardr

Specifications of 237-00156

• Contents: *
• For Use With/related Products: STMicro ST7FMC Motor Control Device
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

6
AK-ST7FMC Control Panel Features
6.3.3 Real-Time Settings
Page 76
Parameter Name
Target Electrical
Frequency
Duty Cycle
Current
Reference
Delay Coefficient
Table 6.4: AK-ST7FMC Control Panel: BLDC Motor Real-Time Settings
Closed Loop target speed. When running in Closed Loop this is a key
parameter because, for a given speed, several other parameters in the
AK-ST7FMC Control Panel main window (BEMF coefficients, PI
control coefficients, sampling time) and in the Advanced Settings
window (software demagnetization, and possibly blanking
windows/event counters) needs to be fine tuned.
This value can be set in Hz or RPM (click the “Hz” or “RPM” button
next to the edit box to switch between units).
Note: if the desired speed cannot be reached, it may be because of the
minimum and maximum speed limits set in the Advanced Settings
window. Please also check that the “Switches PWM Minimum Off
Time” parameter in the Advanced Settings window is not too high
(only when using the STMicroelectronics’ patented three-resistor
BEMF sampling method).
This is an Open Loop, Voltage Mode parameter. It is used to manually
control the speed of the motor.
Note: if the desired duty cycle cannot be reached, it may be because
of the maximum duty cycle set in the Advanced Settings window.
Please also check that the “Switches PWM Minimum Off Time”
parameter in the Advanced Settings window is not too high (only when
using the STMicroelectronics’ patented three-resistor BEMF sampling
method).
MCPUH and MCPUL compare registers.
This is an Open Loop, Current Mode parameter. It is used to manually
control the speed of the motor.
MCPVH and MCPVL compare registers.
Value between 0 and 255 used to compute the delay between the Zero
Crossing event (Z) and the Next Commutation event (C).
Formula: Delay = (Delay Coefficient * ZTime) / 256,
where ZTime is the time between the current Zero Crossing event and
the previous Zero Crossing event (or the previous two if this has been
set in the “Delay Computation” parameter in the Advanced Setting
window). Rising and falling edge detection have been differentiated to
compensate the small delay due to the imbalance in step time.
Imbalance in step time comes from the fact that the Zero Crossing
event is not exactly detected at zero but slightly before (falling BEMF)
or after (rising BEMF). This is caused by threshold voltage and by the
asymmetrical BEMF shape on some motors.
Parameter Description