Siemens SIMATIC S7-300 Manual page 254

Description of Functions
Velocity The manipulated signal calculated by the position controller is available in-
assignment and
ternally on the FM as a velocity setpoint (see position loop gain). To convert
max. voltage
this value to the analog actuating signal, a conversion factor (DAC factor)
setpoint
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 354 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!
23
43
9-78
MD Designation
Maximum speed
Set voltage, max.
Value/Meaning
10...500,000,000
1,000...10,000
FM 354 Servo Drive Positioning Module
Unit
(MSR/min)
(mV)