HEIDENHAIN TNC 151 Q Mounting Instructions page 54

6.2.3.1 Error messages GROSS POSITIONING ERROR and POSITIONING ERROR
The error message GROSS POSITIONING ERROR is displayed for various reasons. In order
to differentiiate the causes of error, the suffixes A - D are displayed:
Error messalge
Cause
GROSS POSITIONING ERROR A, / 0 verstepping of positon supervision, parameter 57 or 174
GROSS POSITIONING ERROR B Overstepping the 10 V nominal value voltage of control in
square root characteristic operation.
GROSS POSITIONING ERROR C Overstepping of limit for movement supervision, parameter 234
GROSS POSITIONING ERROR D. Overstepping of limit for standstill supervision, parameter 169
With parameter 56 or 175 - position supervision (erasable) - and 57 or 174 - positon supervision (emergency
stop), range:s are set for permanent position supervision of the machine. Supervision is operative as soon as
the machine axes are held in closed loops by the control (after traversing over the reference marks).
Overstepping the tolerances in parameter 56 or 175 leads to a control stop and the error display POSITIONING
ERROR.
The error display is cancelled with the
El CE -key.
Overstepping of the tolerances of parameter 57 or 174 leads to a control emergency stop and a flashing error
message GROSS POSITIONING ERROR A. The "emergency stop" must be cancelled by switching off the
mains power.
.~
6.2.4 Mathine parameters which are determined after compilation of parameters for the ramp characteristic
Function
Parameter Possible
No. entry values
Preliminary
entry values
Optimised
entry values
Positioning
range
x, y, z
Axis IV
58
0.001 . . . 0.05 [mm] 0.005
192
The acceptable range which the control recognises as being "position achieved" can be entered with parameters
58 and 192. For example, by entering 0.05, the machine accepts a position within + 0.05 (mm) of the nominal
position as being "position achieved". The control however, still endeavours to position to the nominal value.
Reduction of this positioning range increases the approach time of the machine and the duration from block to
block in automatic program run.
Backlash
compensation
X 36
- 1.000.. . 0
Y 37
+ 1 .OOO [mm/m-) 0
Z
38
0
IV 39
0
For indirect linear measurement with rotary encoders, a small amount of backlash can be present between the
table movement and the rotary encoder. This backlash can be compensated with parameters 36, 37, 38 and 39.
The value 100 urn must, however, not be exceeded.
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