HEIDENHAIN TNC 407 (243 020) Technical Manual - Manual (Page 217)

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TNC 407/TNC 415/TNC 425 3 Servo positioning of the NC-axes 01.98
3.6.4 Open control loop
After Marker M2830 is set, the control loops of each axis and of the spindle are opened, and an NC
stop is performed. This makes it possible, for example, for the control loops to be opened at the
same time as the drives are switched off. If Marker M2827 is set, no external EMERGENCY STOP
(Input I3 “Control is operational”) is sent to the NC; instead, the spindle and the position controllers
are opened in all axes, and an NC stop is carried out.
If, after the execution of an NC block, the control loop for a particular axis is opened and this axis is
clamped, then it is necessary to delay this opening to give the clamp sufficient time to operate. The
markers M2492 to M2495 and M2500 serve this purpose. If one of these markers is set, and the
appropriate axis is in position, then the next NC block will only then be processed when the "Open
control loop" marker (M2544 to M2547, M2507) has been set. After the control loops are opened the
markers M2000 to M2003 and M2016 are reset by the NC. As soon as the "Axis in position" markers
are reset, the control loop must be closed again so that the axis can be moved.
Marker Function Set Reset
M2544 Open control loop X axis PLC PLC
M2545 Open control loop Y axis PLC PLC
M2546 Open control loop Z axis PLC PLC
M2547 Open control loop 4th axis PLC PLC
M2507 Open control loop 5th axis PLC PLC
M2492 Await open control loop X axis PLC PLC
M2493 Await open control loop Y axis PLC PLC
M2494 Await open control loop Z axis PLC PLC
M2495 Await open control loop 4th axis PLC PLC
M2500 Await open control loop 5th axis PLC PLC
M2827 Suppress EMERGENCY STOP, open the
control loop, NC stop PLC PLC
M2830 NC stop and open the control loop PLC PLC
3.6.5 Actual - nominal value transfer
If the markers M2552 to M2555 and M2505 are set, then the actual positional value will be
transferred to the nominal value.
Actual value transfer is only possible in the "Manual" and Electronic handwheel" modes of operation.
Marker Function Set Reset
M2552 Actual - nominal value transfer X axis PLC PLC
M2553 Actual - nominal value transfer Y axis PLC PLC
M2554 Actual - nominal value transfer Z axis PLC PLC
M2555 Actual - nominal value transfer 4th axis PLC PLC
M2505 Actual - nominal value transfer 5th axis PLC PLC