HEIDENHAIN TNC 335 Technical Manual - Manual (Page 566)

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TNC 360 1 PLC Positioning Module 10-5
1.3 EMERGENCY STOP routine
After the TNC has been switched on, the internal EMERGENCY STOP switch-off is checked, i.e. for
each processor the power supply is briefly switched off.
Appropriate circuitry must ensure that the positioning module does not function if an error occurs
during the NC check, i.e. that the voltage for the acknowledgment is mutually switched off. The
circuit illustrated below can fulfill this function. The check is started at the same time that the control
voltage is switched on.
+ –
LE 407/415
After control voltage is switched on, the switch is opened
by each microprocessor for a short time.
X41/34 X44/2 X44/1 X42/4
"Control
operational"
24V Cannot
be switched
off 24V Can be
switched off Acknowledgement
"Control operational"
EMERGENCY STOP
buttons
Control
voltage
on
k1
k1
K1
24 V
PLC
+ –
LE 234.003
After control voltage is switched on, the switch is opened
by each microprocessor for a short time.
X21/34 X24/2 X24/1 X22/4
EMERGENC STOP
buttons
Control
voltage
on
k1
k3
K3
24 V
PLC
k3
"Control
operational"
24V Cannot
be switched
off 24V Can be
switched off Acknowledgement
"Control operational"