VIPA System 200V IM Series, Manual

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Chapter 7 SERCOS - Spare part
Manual VIPA System 200V
7-4 HB97E - IM - Rev. 06/29
SERCOS uses a closed fiber optic ring (FO) as transfer medium. FO has a
high immunity against electromagnetic interference. The ring structure
needs the less number of FO and doesn’t require T-connectors.
Using plastic FO, the length of each transfer section may be up to 50m,
with glass fiber FO up to 250m. The maximum number of participants per
ring is 254.
The exact number depends on the following factors:
•
Required communication cycle time
•
Operating data amount
•
Data rate
The communication happens cyclically during the operation as a master
slave communication. The cyclic time is defined during initialization and
may range between 62µs and 65ms.
This cycle times are specified in a way that the required synchronization
with fixed working cycle times in control and drives is met.
The communication master in a SERCOS ring is always the NC control.
All participants at the bus must be identified by an unique address. Every
SERCOS device has the option to fix the address.
The addressing of the data at the demand control data exchange and the
definition of the real-time data happens with SERCOS via ident numbers.
For the ID numbers, are value range of 2
16
is fixed, divided into two areas:
1 ... 32767: for data (S-0 ... S-7)
32768 ... 65535: for parameters (P-0 ... P-7)
An identifier consists of 2Byte and has the following structure:
0: S
1: P 0 ... 7 0 ... 4095
Example: Coding of S-2-1200
0 0 1 0 0 1 0 0 1 0 1 1 0 0 0 0
FO as transfer
medium
Bus access
procedure
Addressing
ID number for
data exchange