Siemens SINUMERIK 840Di Function Manual page 397

2.3 Setpoint/actual-value system
2.3
2.3.1 General
Control loop
A control loop with the following structure can be configured for every closed-loop controlled
axis/spindle:
Fig. 2-1
Setpoint output
A setpoint can be output for each axis/spindle. Setpoints are output digitally to the actuator
on SINUMERIK 840D/810D.
Actual-value acquisition
A maximum of two measuring systems can be connected for each axis/spindle, e.g. a direct
measuring system for machining processes with high accuracy requirements and an indirect
measuring system for highspeed positioning tasks.
Enter the number of encoders used in machine data:
MD30200 $MA_NUM_ENCS (number of encoders).
In the case of two actual-value branches, the actual value is acquired for both branches.
The active measuring system is always used for position control, absolute value calculation
and display. If both measuring systems are activated at the same time by the PLC interface,
positioning measuring system 1 is chosen internally by the control.
Velocities, Setpoint/Actual-Value Systems, Closed-Loop Control (G2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Block diagram of a control loop
Detailed Description
2.3 Setpoint/actual-value system
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