HEIDENHAIN TNC 426 PB/M Technical Manual page 505

December 2001
Step Function
1 Waiting for machine control
voltage
2 Recognition of the machine
control voltage on X42/4 and
switch-off of the control-is-
ready signal on X41/34 by host
computer (t < 66 ms)
3 Maximum time within which
the control-is-ready
acknowledgment on X42/4
must go to zero (t < 380 ms)
4 Recognition of the
acknowledgment and setting of
X41/34 (t < 20 ms)
5 Waiting for machine control
voltage
6 Recognition of the machine
control voltage on X42/4 and
switch-off of the control-is-
ready signal on X41/34 by DSP
(t < 120 ms)
7 Maximum time within which
the control-is-ready
acknowledgment on X42/4
must go to zero (t < 380 ms)
8 Recognition of the
acknowledgment and setting of
X41/34 (t < 120 ms)
9 Waiting for machine control
voltage
10 Normal control operation.
Control-is-ready output and
acknowledgment are high.
11 Control voltage is switched off
externally.
12 After switching on again, the
machine control voltage can be
switched off, and then the
control operates normally.
13 After detecting a fault, the
control switches off the control-
is-ready output (X41/34).
Monitoring Functions
Screen display
RELAY EXTERNAL DC VOLTAGE
MISSING
If exceeded EMERGENCY STOP
DEFECTIVE
RELAY EXTERNAL DC VOLTAGE
MISSING
If exceeded EMERGENCY STOP
DEFECTIVE
RELAY EXTERNAL DC VOLTAGE
MISSING
EMERGENCY STOP
Blinking error message
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