HEIDENHAIN TNC 306 Service Manual - Manual (Page 53)

SERVICE MANUAL TNC 306/360
Page 46
HEIDENHAIN Service
11. Encoders
11.1 Error Messages
ENCODER DEFECTIVE X
X = A Signal amplitude too low
B Frequency exceeded
C Wrong reference mark spacing
11.2 Error Causes
- Glass scale contaminated or damaged
- Scanning head contaminated or defective
- Cable damaged
- Encoder input of the LOGIC UNIT (LE) defective
11.3 Checking the Encoders
In order to determine whether the encoder or the encoder input of the LOGIC UNIT
is defective, the encoders can be switched at the LOGIC UNIT. For this purpose,
the corresponding machine parameters must be altered as well.
Function MP Input Values
Allocation of the axes X
to the encoder inputs Y
Z
IV
110.0
110.1
110.2
110.3 0 = X1
1 = X2
2 = X3
3 = X4
4 = without function
5 = X61)
1) X6 can be used for a machine tool axis, if no spindle orientation is required.
Procedure if an error message is displayed:
e.g.: ENCODER X DEFECTIVE B
- Switch off main switch.
- Switch encoder X-axis with e.g. encoder Y-axis at the logic unit.
- Switch on main switch.
- If the error message "POWER INTERRUPTED" is generated, call the machine parameters
with the code number 95148 and switch the input values of the machine parameters
110.0 and 110.1.
- Exit the machine parameters and switch on the machine as usual. If the same error
message "ENCODER X DEFECTIVE B" is generated again, the error is due to the
encoder or to the extension cable.If the errror message now says "Y" instead of "X" the
encoder input of the LOGIC UNIT is defective.