Siemens SINAMICS S120 Installation And Start-Up Manual page 141

Position controller
cycle
Master
(position controller)
MSG RES GC
Speed
controller
cycle
R R R R R R
R R
Slave
1 to 3
T
I
Fig. 4-17 Example: Optimized cycle with T
Sequence of data transfer to closed-loop control system
1. Actual position value G1_XACT1 is read into the telegram image at time T
before the start of each cycle and transferred to the master in the next cycle.
2. Closed-loop control on the master starts at time T
controller cycle and uses the current actual values read previously from the
slaves.
3. In the next cycle, the master transmits the calculated setpoints to the telegram
image of the slaves. The speed setpoint command NSETP_A is issued to the
closed-loop control system at time T
Designations and descriptions for Motion Control
Table 4-18 Time settings and meanings
1)
Name Value
T 5DC hex
BASE_DP
8
1500 dec
T 8
DP
E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
T
MAPC
T
DP
T
M
R1 R2 R3
Dx Dx Dx MSG RES
R R R R R R R R R R R R R R R R R R R
= 2 S T
MAPC
Limit value
– Time base for T
Calculation: T
T
Bit
w T
T Cycle time
DP DP_MIN
T
DP
Calculation: T
Communication via PROFIBUS
Motion control with PROFIBUS
= 2 S T
DP
T
DX
GC Dx Dx Dx MSG RES
R R R R R R R R R R R R R R R R R R R R R
T T
I O
DP
after each position
M
after the beginning of the cycle.
O
Description
DP
= 1500 S T
BASE_DP
= 1/12 µs at 12 Mbaud
= integer multiple S T
BASE_DP
= 8 S T
DP BASE_DP
T
M
R1 R2
GC Dx Dx Dx MSG
R R R R R R R R R R R R R R R
T
I
I
= 125 µs
Bit
= 1 ms
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