Dsc (Dynamic Servo Control) - Siemens SINUMERIK 840Di sl Commissioning Manual

Assignment of the 2nd measuring system (index 1) of the machine axis to the measuring
circuit input of the ADI4 module is performed via the axis-specific machine data:
● MD30220 $MA_ENC_MODUL_NR[1] = 4
For this, see Subsection "Setpoint value/actual value channels" (Page 393).
Machine data
Table 11-22 Drive configuration: Machine data
Number Name
General ($MN_ ... )
13050 DRIVE_LOGIC_ADDRESS[n]
13060 DRIVE_TELEGRAM_TYPE[n]
30220 ENC_MODULE_NR[0]
30220 ENC_MODULE_NR[1]
Interface signals
Table 11-23 Switchover of position measuring system: Interface signals
DB number Bit, byte
Axis/spindle-specific
31, ... 1.5
31, ... 1.6
11.5.8

DSC (Dynamic Servo Control)

The DSC function eliminates the deadtime that necessarily exist at the speed setpoint
interface normally used between the NC and drive due to relocation of the position controller
into the drive.
That results in the following advantages for an axis operated with DSC:
● Considerably improved fault response/stability of the position control loop
● Improved control behavior (contour precision) if the higher servo gain (Kv factor) that can
● A reduction of the cyclic communication load on the PROFIBUS, if the position control
Manual
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
with 4 = (Index 3 of the corresponding MD13050 + 1)
Name
Signals from PLC to axis/spindle
Position measuring system 1
Position measuring system 2
be set in conjunction with DSC is used.
cycle/PROFIBUS cycle is reduced by adjusting the above parameters, even if the control
loop performance is the same.
NC Commissioning with HMI Advanced
Name/remarks
Logical I/O address of drive
Drive message frame type for the drives connected to
PROFIBUS DP
Actual value assignment: Logical drive number for position
measuring system 1
Actual value assignment: Logical drive number for position
measuring system 2
11.5 Axes and spindles
405