Siemens SINUMERIK 840D sl Function Manual page 347

Activation
The following conditions must be fulfilled so that the temperature compensation can be
activated:
1. The compensation type is selected (MD32750, see "Temperature compensation type and
2. The parameters for the compensation type are defined (see "Temperature-dependent
3. The axis is referenced:
As soon as these conditions are fulfilled, the temperature compensation value for the
position actual value is added to the setpoint in all modes and the machine axis traverses
through this distance. If the compensation value ∆K
negative direction.
If the reference position is then lost, e.g. because the encoder frequency has been exceeded
(DB31, ... DBX60.4 or 60.5 = 0), compensation processing is deactivated.
Clock cycle
The compensation values are determined in the interpolation cycle.
Display
The total compensation value calculated from the temperature and sag compensation
functions belonging to the actual position is output in the "Service axes" display in the
"Diagnosis" operating area.
Parameter adaptation for temperature changes
Since the approximated error line applies only to the instantaneous temperature value, the
parameters of the error lines that are newly generated when the temperature rises or falls
must be sent to the NCK again. Only in this way can expansion due to heat always be
correctly compensated.
When temperature T changes, the parameters which are temperature-dependent, i.e. (K
tanβ and P
synchronized action.
It is thus possible for the machine-tool manufacturer to emulate the mathematical and
technological relationship between the axis positions and temperature values via the PLC
user program and thus calculate the various parameters for the temperature compensation.
The temperature parameters are transferred to the NCK using the variable services (FB2
(GET) "Read data" and FB3 (PUT) "Write data").
For more information on handling and supplying FB2 and FB3 see:
Reference:
Function Manual Basic Functions; Basic PLC Program (P3)
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
activation (Page 348)").
parameters (Page 348)").
DB31, ... DBX60.4 or 60.5 =1 (referenced/synchronized 1 or 2 respectivelly)
) also change and can thus always be overwritten by the PLC or by means of a
0
5.2 Temperature compensation
is positive, the axis moves in the
x
K3: Compensation
,
0
347