July 2010 3 – 687
3.3.13 EMERGENCY STOP monitoring during operation
On the control there is a PLC output (X41/34) with the designation control-is-ready, and the
associated PLC-input for the MC (X42/4; I3) with the designation control-is-ready-
acknowledgement for the EMERGENCY STOP routine.
Internal
EMERGENCY STOP
If a functional error (e.g., standstill monitoring) is recognized, the iTNC generates an internal
EMERGENCY STOP.
The iTNC ...
switches off the "Control is ready" output.
(SH1A; responsible watchdog reacts after 10 ms at the latest)
switches off the inverter enables, and thus the inverters are without power.
(SH1B; responsible watchdog reacts after the time set in MP2172 of 1 to 6 s).
An error message appears and the PLC program is stopped.
Depending on the error class, it might be possible that cannot be cleared with the CE key:
8 Correct the error and restart the switch-on routine.
--> See “During Start-Up” on page 3 – 661!
MP2172 Delay for the SH1B signal (inverter enable)
Input: 0 to 6 [s] as an integer
0: 3 [s] Default
External
EMERGENCY STOP
via MC (I3)
If an external EMERGENCY STOP is triggered via input I3 ("acknowledgment of control-is-ready
signal"),
the nominal speed value "null" is output via the MC, braking the drives on the intended braking
ramp (usually at the limit of current).
the EMERGENCY STOP error message is displayed.
markers M4177 and M4178 are set by the NC.
You can clear the error message with CE after switching the machine control voltage back on.
The input I3 ("control-is-ready signal acknowledgment") is passed directly onto the NC; it can not
be manipulated by the PLC (I3).
Resetting the “control-is-ready signal acknowledgment” inputs leads to position monitoring
being shut off for the time defined in MP1150.1, and to an actual-to-nominal value transfer. After
the time defined in MP1150.1 has expired, position monitoring is again active, for at least the
time defined in MP1150.2.
If marker M4580 is set, then instead of the external emergency stop ("control-is-ready signal
acknowledgment" input), the control loops of all axes and of the spindle are opened, and an NC
stop is performed.
Set Reset
M4177 Clearable error message displayed NC NC
M4178 Error message EMERGENCY STOP is displayed NC NC
M4580 Suppress EMERGENCY STOP, open all position control loops,
NC stop
PLC PLC