HEIDENHAIN iTNC 530 HSCI - Emergency Stop Monitoring

930 HEIDENHAIN Technical Manual iTNC 530 HSCI
6.11.14 Emergency stop monitoring
For the emergency stop routine of the iTNC 530 HSCI without functional
safety (FS), the PLB has the PLC "control-is-ready" output X9/3a (-STO.A.G) and
the two emergency stop inputs -ES.A (X9/7a) and -ES.B (X9/7b) (ES:
Emergency Stop). The delayed control of the safety relay in the compact
inverters or supply units (X71, X72) over the PLC output -STO.A.G is
mandatory. Please read the corresponding basic circuit diagram.
The -STO.A.G output signalizes the readiness of the control and is = 1 until one
of the following conditions is met:
 Controller unit reports fatal error
 Controller unit reports an error with an emergency stop as reaction
 Main computer reports fatal error
 Main computer reports an error with an emergency stop as reaction
 PLC, PLC program reports an error with an emergency stop as reaction
 No PLC program is run
As a result of these events, -STO.A.G becomes 0. When the error message
is acknowledged, -STO.A.G become 1 again and the control is again ready for
operation. To prevent that the control then immediately goes into closed-loop
mode, the -STO.A.G signal must be wired into the emergency stop chain
(-ES.A, -ES.B). Switching -STO.A.G off must result in a switch-off of the -ES.A
and -ES.B inputs. This triggers additionally an external emergency stop. In
addition, -STO.A.G = 0 must remove the latch circuit of the machine control
voltage. This makes it possible to switch the machine back on by means of
"Control voltage on."
On the PLB, for example, the -ES.A and -ES.B are available for triggering an
emergency stop on the iTNC 530 HSCI with functional safety (FS). However,
the wiring of the safety relays in the compact inverters or power supply units
via the PLC outputs STO.A.G and STOS.A.G is then optional. Please note the
special documentation for controls with functional safety (FS) an the
corresponding basic circuit diagram!
Note
Switching STO.A.G off must result in a switch-off of the -ES.A and -ES.B
inputs.