Service Manual TNC 407 / TNC 415 - heidenhain - DR. JOHANNES ...

Cams for "Reference End Position":
The reference marks can either be traversed manually using the axis direction keys or automatically with the start key. It is not necessary to enter a code number
for the manual traverse as was the case with preceding TNC models. The traverse direction for automatic traverse of the reference marks is defined in MP1320.
In order to reverse the traverse direction at the end of the traverse range, a cam for "reference end position" is required. The trigger signals "ref. end position" are
assigned to free PLC inputs. By the PLC software these PLC inputs are connected to the PLC markers M2506 and M2556 to M25599. Depending on the entry value
of MP1350 the TNC behaves differently.
Linear Encoder with Distance-Coded Reference Marks (MP 1350.X = 0), Mode 1
If the trigger signal "ref. end position" is set when starting reference mark traverse, the axis moves in the direction opposite to that set in the MP1320. If the trigger
signal "ref. end position" is only set during automatic traverse, the TNC ignores this signal. Thus, there must be at least two reference marks within the range of the
"reference end position". Ref. mark evaluation takes place either in the range of the "ref. end position" or else beyond this range. In case of an evaluation beyond the
software limit switch range, the axis automatically moves to the software limit switch after evaluation.
Linear Encoder without Distance-Coded Reference Marks (MP 1350.X = 1)
The traverse direction is automatically reversed, if the axis traverses the cam for "ref. end position". If the axis is already in the range of the "reference end position"
range when starting, it moves immediately in the opposite direction. For this reason the reference mark has to be outside the "ref. end position" range.
Special Operation: Linear Measurement with a Rotary Encoder (MP1350.X = 2)
The axis automatically moves to the cam for "reference end position" at the defined feed rate (MP1330). This axis is started again at a reduced feed rate (MP1331)
in the opposite direction; the first reference mark is evaluated after the end of the "reference end position" range has been reached. Then the axis is stopped. If the
axis is already in the "reference end position" range when starting, it moves immediately at the reduced feed rate (MP1331) in the direction opposite to that indicated
in MP1320.
Linear Encoder with Distance-Coded Reference Marks (MP1350.X = 3), Mode 2
If the trigger signal "reference end position" is set during reference mark traverse, the axis moves opposite to the direction defined in MP1320. The signal "ref. end
position" is not ignored by the NC. it is only set during automatic traverse. The traverse direction is reversed immediately. Thus, no reference marks are required
in the "ref. end position" range.
RH
1.0 TNC 407/415 Machine Parameters MP 1350.X 16.01.95 10.2 14