HEIDENHAIN TNC 122 Technical Manual User Manual
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TNC 122
9 Machine Integration
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Offset compensation
An offset error can be compensated. An offset error exists if the axis drifts when the controller input
is supplied with 0V analog voltage. If the axis does drift, an offset voltage must be output to prevent
the drifting. To define the analog offset voltage, press MOD and enter the code number 75 368 to
call the “AV OFFSET” dialog prompt. The optimum input value (a multiple of 2.93 mV = 1
transformer step) must be determined empirically. Before this, the bottom voltage must be set to
zero with MP1051. For bipolar drives, enter the proper algebraic sign for the voltage.
Feed rate enable
It is only possible to move the axes if the feed rate enable is present in marker M2451 and
complementary marker M2467. If the feed rate enable is removed, the analog voltage output is 0 V
and the axes stop moving immediately.
Set
Reset
M2451
Feed rate enable
PLC
PLC
M2467
Complementary feed rate enable
PLC
PLC
Axes in position
When the axes have reached the defined positioning window (MP1030.x), the “Axis in position”
markers are set by the NC. This is also done when the control voltage is switched on.
The markers will only be reset by the NC if the axes leave the positioning window when being
traversed. This also applies when the reference marks are crossed over.
Set
Reset
M2008
Axis X in position
NC
NC
M2009
Axis Y in position
NC
NC
M2010
Axis Z in position
NC
NC
Open the control loop
In order to lock or disengage an axis, the control loop must be opened by the PLC. As soon as the
“Axis in position” markers (M2008 to M2010) are reset, the control loop must be closed again so
that the axis can be moved. Before the control loop is closed, an actual and nominal value transfer
must be performed.
Set
Reset
M2544
Open control loop axis X
PLC
PLC
M2545
Open control loop axis Y
PLC
PLC
M2546
Open control loop axis Z
PLC
PLC
Actual/nominal value transfer
If markers M2552 to M2554 are set, the momentary actual position value is taken as the nominal
position value.
Set
Reset
M2552
Actual/nominal value transfer axis X
PLC
PLC
M2553
Actual/nominal value transfer axis Y
PLC
PLC
M2554
Actual/nominal value transfer axis Z
PLC
PLC