December 2001 Monitoring Functions 6 – 173
6.11.12 EMERGENCY STOP Monitoring
On the control there are the PLC input I3 (X42/4) and a PLC output (X41/34) 
with the designation control-is-ready for the EMERGENCY STOP routine.
If a functional error is detected, the TNC switches the control-is-ready output 
off. A blinking error messages appears and the PLC program is stopped. You 
cannot clear this error message with CE:
7
77
7 Correct the error and restart the switch-on routine.
If the “control-is-ready signal acknowledgement” input is switched off by a 
process external to the control, the error message EXTERNAL EMERGENCY STOP 
appears. The NC sets M4177 and M4178. The nominal speed value 0 is output 
and the drives are switched off. You can clear this error message after 
switching the machine control voltage back on. 
7
77
7 In MP1152, define the interrogation of the “control-is-ready signal 
acknowledgement” input. If MP1152 = 0, the input is interrogated directly 
by the NC (in the position controller cycle). If MP1152 = 1, the input is 
processed by the PLC (in the PLC cycle) before being passed on to the NC.
Resetting the “control-is-ready signal acknowledgement” 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 acknowledgement” input), the control loops of all 
axes and of the spindle are opened, and an NC stop is performed.
MP1152 Interrogation of I3 “Control-is-ready signal 
acknowledgement”
Input:  0: I3 is passed on directly to the NC
1: I3 is processed by the PLC before being passed on to the NC
Warning
MP1150.1 = 0 switches position monitoring off! Safe machine operation is 
not possible if the position monitoring function is switched off. 
Uncontrolled machine movements will not be detected!
Set Reset
M4177 Erasable error message is 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