Receiver/Transceiver, Machine Interface - As-I Safety At Work - Siemens SIMATIC FS400 Anleitung

7.4.2 Receiver/transceiver, machine interface - AS-i Safety at Work

Both the data communication with the AS-i Master and the receiver/transceiver supply
are made via the direct connection of the receiver/transceiver device. The receiver/
transceiver must be programmed with an AS-i address for the data retrieval with the
bus master.
The machine interface - AS-i Safety at Work delivers the AS-i Safety at Work-specific
code sequence, which the AS-i safety monitor saves and monitors permanently when
the safety monitor is started.
The receiver/transceiver machine interface - AS-i Safety at Work at the AS-I side has
the following internal schematic structure. The data port of the AS-i chip is illustrated.
OSSD1 OSSD2
D0.......D3
Data Port
a = Sensor
b = AS-i slave (integrated)
Fig. 7.4-3: Receiver/transceiver, machine interface - AS-i Safety at Work, schematic
structure
The potential-separated OSSD outputs control the generator for the code sequence,
which supplies the cyclically changing 4 data bits as long as both OSSD = 1. The data
bits are evaluated by the AS-i safety monitor.
With SIMATIC FS400 3SF7842 - AS-i Safety at Work device variants the restart
interlock (RES) and contactor monitoring (EDM) functions are not integrated, as these
functions can always be configured via the AS-I safety monitor. You will find more
details on this in the asimon configuration and diagnostics software user manual for
AS-i safety monitors.
As a protective measure against damage caused by electrostatic discharge of the
device it is recommended that the housing profile of the device be earthed.
Detailed information on AS-i Safety at Work and the AS-i safety monitor can be found
in the connecting and operating instructions manual of the AS-i safety monitor.
172
a
b
AS-i +
AS-i -