Siemens SIMATIC FM 453, Manual

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9-85
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
Velocity/voltage assignment
The manipulated signal calculated by the position controller is available in-
ternally on the FM as a velocity setpoint (see position loop gain). To convert
this value to the analog actuating signal, a conversion factor (DAC factor)
within the FM is necessary. This factor is formed as the quotient of MD43
and MD23. MD23 contains the configured maximum speed of the machine
axis, and MD43 contains the voltage setpoint of the actuating signal to be
output by the FM 453 for this purpose; as a compromise between the highest
possible resolution and adequate close-loop control reserve, this voltage
should lie between 8 V and 9.5 V.
!
Warning
This assignment MUST be identical with the setting on the drive!
MD Designation Value/Meaning Unit
23 Maximum speed 10 ... 500 000 000 (MSR/min)
43 Set voltage, max. 1,000...10,000 (mV)
Voltage ramp
A ramp-shaped voltage rise/drop can be defined in MD45 for the voltage out-
put to the drive when the position controller is inactive. This serves to limit
acceleration and thus power for the drive controller, and is preferable to set-
ting options that may be available on the drive, since it has no adverse effects
on active position control.
The voltage ramp is active in the following situations:
S
Continuously in “Control” mode
S
Deceleration on cancelation of the drive enable [AF] (see Section 9.1.1)
S
Deceleration on transition of CPU from RUN to STOP
S
Deceleration on error response “Everything Off” (see Sections 11.1, Tab.
11-4 and 11-5)
MD Designation Value/Meaning Unit
45 Voltage ramp 0...10,000,000 (mV/s)
Description of Functions