09.2008
Communication / PROFIBUS
Siemens AG
6SE7087-6QX70 (Version AK)
SIMOVERT MASTERDRIVES
Compendium Motion Control
8.2-83
8.2.8.6
CBP2 with clock synchronization operated with a SIMATIC S7
CBP2 with clock synchronization is not supported by MASTERDRIVES
VC.
Clock synchronization enables the synchronization of several
MASTERDRIVES MC at the isochronous PROFIBUS.
You need
♦
STEP7 Version 5 or higher
♦
DriveES with slave OM for CBP2
♦
SIMATIC S7 as PROFIBUS master with “clock synchronization”
feature
♦
CBP2 from V2.21
♦
MASTERDRIVES MC (Compact or Compact PLUS) software version
V1.4 or higher
You can configure clock synchronization in the Step7 HW configurator
-> Object properties -> tab "Clock synchronization".
The isochronous DP cycle must have been tuned to the pulse frequency
of the drive. The following combinations are possible with the default
pulse frequency of 5.0 kHz and a PROFIBUS transmission rate of
12 Mbit/s:
Synchronized time slot
in the basic unit
DP cycle
Max. number of DP
slaves
T4 3.2
ms 11
T5 6.4
ms 27
Measures relating to bus configuration:
♦
First, configure all DP slaves, possibly with cross traffic. The
quantities and the minimum DP cycle on the PROFIBUS are thus
defined.
♦
In the "Equidistance" register (can be reached under "PROFIBUS",
"Properties", "Supply settings", "Options"), activate the isochronous
bus cycle. You must repeat this step if you alter the bus configuration
(deactivate Equidistance and re-activate)!
♦
In the “clock synchronization” tab of the drive, activate “Clock
synchronization” for every drive. As default, time slot T4 is set at 3.2
ms.
♦
It must be ensured that the difference between "DP cycle" and
"Equidistance master cycl. part" is at least 1 ms. The CBP2 needs this
time to pass the data between PROFIBUS and the basic board
consistently.
♦
The "Align" button ensures that all MASTERDRIVES MC are given
the same settings for clock synchronization and that the DP master
adopts the isochronous DP cycle.
Cycle times
STEP7 bus
configuration