SPACE 2000 EVO/N (T and M versions) OPERATION MANUAL
14
RULER ZERO REFERENCE (rEF)
The ruler zero reference (rEF) can be considered a precision micro-contact, generally
located at the centre point of the travel. Its position in relation to the geometrical trim of the
machine is invariable in time, and can only “move” if the ruler is disassembled (for
servicing, maintenance or replacement), and re-assembled differently. In this case the
operator will have to set the references again. When using scales with reference marks at
coded distance, the research of rEF is completed after a travel about 20mm on the travel
direction.
Note: for a correct recognization of ref. position, on scales with reference marks at coded
distance, it is important to properly set the counting way, according to the installation
instruction.
The zero can be searched either in the
automatic mode,
each time the instrument is
switched on, or in the
manual mode:
A)
Automatically,
each time there is a momentary or long-lasting interruption of the
main power supply, either voluntary or otherwise, in order to avoid presenting the
operator with incorrect numerical values (LAST POSITION), the instrument displays a
prompt to the operator suggesting a new ruler zero (rEF) search. This is the case, for
example, in the event of a sudden power failure occurring while the Carriage is
moving (since it would continue to move due to inertia), or movements due to thermal
expansion (due, perhaps, to a temperature drop at night), or involuntary or accidental
shifting (while cleaning the machine, for example). In this way, the operator is warned
that there is a probable “risk situation”. He may decide to carry out a ruler zero (rEF)
search by passing the Carriages over the corresponding points, or else to cancel the
ruler zero by pressing CLR (this should be done in any case if the rulers do not have
the ruler zero reference.
In this case it is advisable to check the precision of the
positions reached
).
B)
Each time the operator feels that it is necessary, he can check the positions reached
by the Carriages by setting the ruler zero (rEF) search
manually
on the Axis in
question (or on all the Axes).
For example enter:
X
and/or
Key
and/or
and/or
r E F
Y
and/o
Z
The LEDs of the activated Axes flash and indicate that the instrument is ready for the ruler
zero (rEF) operation
NOTES:
Each time an Axis completes the ruler zero (rEF) search, it is automatically excluded from this
function so that it will not interfere with the other operating conditions. In any case, the instrument
will not accept any settings until all the Axes have terminated the ruler zero (rEF) search, and will
display an error message if any keys except CRL are pressed. The operator may then decide to
proceed as follows:
A) to complete the zero search for all the Axes activated;
B) to carry it out for the Axis concerned and cancel it for the remaining Axes;
C) to cancel the search right away for all the Axes because it is considered superfluous.
