▶
Short circuit against GND or VCC: Safety is ensured because the output signal is
permanent. The PLC cannot detect pulsing anymore.
8.2.1
OSSD Monitoring: Speed zero
The signal for “Speed zero” is a status signal. The PLC makes the signal active HIGH.
By closing the relay the signal chain is closed and the PLC receives its signal. If a drive
fails to send the “Speed zero” signal, the relay remains open and the signal chain is
interrupted.
The PLC sends OSSD signals to both drives A and B. The OSSD signals are 2-
channel signals. Each signal for each drive is passed through 2 electronic relays
before it is fed back to the PLC. Each safety controller controls one of the two relays of
each OSSD channel. When the safety controllers detect “Speed zero” at the drives,
they switch the corresponding relays.
Internal requirements for switching the relays and for testing:
▶
No SYNC signals are counted at the motor control.
▶
The comparators must have detected “Speed zero”.
▶
The other safety controller must signal “Speed zero” for the respective drive.
8.2.2
OSSD Monitoring: Frequency Limitation
The PLC sends OSSD signals to both drives A and B. The OSSD signals are 2-
channel signals. Each signal for each drive is passed through 2 electronic relays
before it is fed back to the PLC. Each safety controller controls one of the two relays of
each OSSD channel. When the safety controllers detect “Safe Limited Output
Frequency” at the drives, they switch the corresponding relays.
8.2.2.1
With Frequency Limitation
Internal requirements for closing the relays and for testing:
▶
At the motor control the signal “Safe Limited Output Frequency” must be detected.
▶
The comparators must have detected “Safe Limited Output Frequency” (currently
not used).
▶
The other safety controller must signal “Safe Limited Output Frequency” for the
respective drive.
▶
An error must not be present.
8.2.2.2
Without Frequency Limitation
Internal requirements for closing the relays:
▶
An error must not be present.
OSSD self tests of the relays are not executed.
OSSD Signals
W
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Drive System SD2 - Safety Functions SFM / SLOF
8
Содержание SD2
Страница 1: ...Drive System SD2 Safety Functions SFM SLOF P TD 0000426 12 2019 08 28 SIEB MEYER W ...
Страница 4: ...Chapter Overview W 4 Drive System SD2 Safety Functions SFM SLOF ...
Страница 10: ...General Information W 10 Drive System SD2 Safety Functions SFM SLOF 2 ...
Страница 16: ...Safe Frequency Monitor SFM W 16 Drive System SD2 Safety Functions SFM SLOF 3 ...
Страница 44: ...Fieldbus Communication W 44 Drive System SD2 Safety Functions SFM SLOF 6 ...
Страница 56: ...OSSD Signals W 56 Drive System SD2 Safety Functions SFM SLOF 8 ...
Страница 66: ...Error Messages W 66 Drive System SD2 Safety Functions SFM SLOF 10 ...