USA57 Revision
1.2
81
Also the opto sensors and switches are interchangeable. If four opto sensors are desired, power
for the extra opto sensors can be drawn from the 5V supply on the encoder connector. These
extra opto sensors may require an external resistor in series with the LED. When connecting
any external switches, connect them between any input and ground.
Main Axis Homing Details:
There are four full steps in a single electrical cycle that moves the stepping motor. (A+, B+, A-,
B-). For repeatability in homing, the home position is set to first step in that cycle (A+) that
occurs after the flag edge has been seen. (This means that the home position is defined some
ways beyond the middle of the flag).
However, there is a small but finite chance that an ambiguity in home position may occur in the
rare case that the exact point of switching into A+ occurs at the same point at which the flag is
interrupted. In the case where a 4 step ambiguity in home position may exist because the flag
may sometimes be interrupted just before and sometimes just after, the procedure below
describes a method by which the ambiguity can be removed. However, this procedure need not
be followed if a 4 step inaccuracy in Home position is acceptable.
To eliminate the home position ambiguity, first issue the Z command, allow the motor to home.
Then move 2 full steps (in any direction), now mechanically move the flag edge (or sensor) such
that it trips in the middle of the sensor by adjusting it while watching the status LED on the board
which shows the status of the home sensor. This will ensure that the flag trips at A- and thus the
motor will home to a unique position of A+.
Another way to do this, if it is not hazardous, is to put the motor in an endless homing loop
“/1gZ10000GR”, then move the flag/opto around while the motor is homing. It will be noticed
that the motor will home to two distinct positions that are 4 steps apart. Make sure the High to
Low transition point of the Opto sensor is NOT near these positions (exact position does not
matter as long as it is not near the place where it homes to).
Second Axis Homing Details:
The second axis will home to the exact transition of the home flag, and does not seek a Phase
A zero. The second axis uses the switch inputs for homing and limits.
Manual homing:
Motors can be manually homed to any input by the use of a polling loop such as:
/1s1z0R Set the current position to zero and store to storage location #1
/1z100000gD1S04e1GR Move backwards in an endless loop until input #4 goes High .
Содержание Accuriss 57 Series
Страница 1: ... USA57 Revision 1 2 Accuriss 57 Series Integrated Motor Drive Control System USA57 USER S MANUAL ...
Страница 4: ...USA57 Revision 1 2 4 Appendix I 101 Appendix J 103 ...
Страница 11: ...USA57 Revision 1 2 11 ...
Страница 102: ...USA57 Revision 1 2 102 Encoders must have 0 2V Low to 4V High swing at the input of the connector ...