Communication via PROFIBUS
Motion control with PROFIBUS
4-143
E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
Table 4-18 Time settings and meanings, continued
Name DescriptionLimit valueValue
1)
T
PLL_W
0 – PLL window
(half the width of the GC synchronization window)
The following applies to the setting:
S Small window –> minimization of synchronization
fluctuations on the drive
S Large window –> higher tolerance of GC fluctuations
Calculation: (assumption: T
PLL_W
= A hex 10 dec)
T
PLL_W
= 10 S T
BIT
= 0.833 µs
T
Bit
= 1/12 µs at 12 Mbaud
T
PLL_D
0 – PLL dead time
The PLL dead time can be used to compensate for dif-
ferent data transfer times to the slaves (e.g. due to re-
peaters).
The slaves with faster transfer times are delayed with a
corresponding PLL dead time.
Calculation: T
PLL_D
= 0 S T
BIT
= 0 µs
T
Bit
= 1/12 µs at 12 Mbaud
GC Global Control telegram (broadcast telegram)
T
TH
Token hold time
This time is calculated by the engineering system.
Dx Data_Exchange
This service is used to implement user data exchange
between master and slave 1 – n.
MSG Acyclic service
After cyclic transmission, the master checks whether the
token hold time has already expired. If not, another
acyclic DPV1 service is transmitted.
RES Reserve: “Active pause” until expiry of the isochronous
cycle
R Processing time for speed or position controller
T
M
Master time
This is the time from the start of the position controller
cycle to the start of master closed-loop control.
GAP Attempt to open connection with new node.
This attempt takes place every xth cycle.
T
J
T
J
returns the duration of the cycle jitter.
The cycle jitter is the delay of the GC telegram.
1) The values correspond to device master file si0280e5.gs_
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