Efficient Networks Siemens Sinamics S120 - Manual (Page 419)

Communication PROFIBUS DP/PROFINET IO
10.2 Communication via PROFIBUS DP
Drive Functions
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
419
Name Value 1) Limit value Description
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 the isochronous cycle has expired
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_
Setting criteria for times
● Cycle (T
DP
)
– T
DP
must be set to the same value for all bus nodes.
– T
DP
> T
DX
and T
DP
≧ T
O
T
DP
is thus large enough to enable communication with all bus nodes.
NOTICE
After T
DP
has been changed on the PROFIBUS master, the drive system must be
switched on (POWER ON) or the parameter p0972=1 (Reset drive unit) must be set.
● T
I
and T
O
– Setting the times in T
I
and T
O
to be as short as possible reduces the dead time in the
position control loop.
– T
O
> T
DX
+ T
Omin
● A tool is available for setting and optimization purposes (e.g. HW Config in SIMATIC S7).
The following must be noted:
– Configuring reserves allows the following:
Class 2 masters can be connected
Non-cyclic communication
Minimum times for reserves
Table 10-32 Minimum times for reserves
Data Time required [µs]
Basic load 300
Per slave 20