VIPA System 200V IM Series, Manual

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Manual VIPA System 200V
Chapter 7 SERCOS - Spare part
HB97E - IM - Rev. 06/29 7-3
Basics
SERCOS means
Se
rial
R
eal Time
C
ommunication
S
ystem and has been
established for numeric controls all over the world. Beyond the classic CNC
machines this technique has proofed its worth as fast and precise motion
control in the whole automation branch.
SERCOS, also called "SERCOS Interface", is a standardized digital drive
interface based on fiber optic transmitter technology.
The high real-time demands and the interference secure fiber optic techno-
logy are distinguishing features of this bus system.
With the SERCOS coupler IM 253SC from VIPA, the SERCOS connection
to the sensor/actuator level is now possible.
The SERCOS coupler is anticipated for the fast data exchange at the
sensor/actuator level. Here, central controls, like e.g. a PLC, communicate
with decentral in- and output modules via a fast serial connection. The data
exchange with this decentral devices is executed cyclically.
The master reads the input information from the slaves (drive telegram)
and sends the output information to the slaves (master data telegram).
A maximum of 254 slaves may be connected to one bus.
SERCOS knows three kinds of telegrams for the communication:
•
Master-Sync telegram
The Master-Sync telegram is received simultaneously by all drives and
serves the synchronization of all time related commands of the numeric
control (NC) and drives.
•
Master-Data telegram
The Master-Data telegram is also received by all drives simultaneously.
It contains the cyclical data and service data for all drives.
•
Configurable data field
The real-time data is completely transferred in every communication
cycle in the so called configurable data field. The drives are sending
their telegrams in sequence during assigned time windows. With the
help of an ident no. system, the real-time data to send may be fixed
during initialization. You may transfer numeric data like set point and
effective values as well as bit lists with in-/output commands.
The exchange of service data needs a request from the master. Service
data is transferred with a handshake procedure in 2, 4, 6 or 8Byte portions
in the service data field "Info" and assembled again at the recipient.
SERCOS
Communication