User manual

PD-1141 TMCL Firmware V1.19 Manual (Rev. 1.01 / 2012-JUL-27) 74
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6 Hints and Tips
This chapter gives some hints and tips on using the functionality of TMCL, for example how to use and
parameterize the built-in reference point search algorithm.
6.1 Reference Search
The built-in reference search features switching point calibration and support of one or two reference
switches. The internal operation is based on a state machine that can be started, stopped and monitored
(instruction RFS, no. 13). The settings of the automatic stop functions corresponding to the switches (axis
parameters 12 and 13) have no influence on the reference search.
Note:
Until the reference switch is found for the first time, the searching speed is identical to the maximum
positioning speed (axis parameter 4), unless reduced by axis parameter 194.
After hitting the reference switch, the motor slowly moves until the switch is released. Finally the switch
is re-entered in the other direction, setting the reference point to the center of the two switching points.
This low calibrating speed is a quarter of the maximum positioning speed by default (axis parameter 195).
The reference switch is connected in series with the left limit switch. The differentiation between the left
limit switch and the home switch is made through software. Switches with open contacts (normally
closed) are used.
CHOOSE ONE OF THESE VALUES FOR AXIS PARAMETER 193:
Value
Description
1
Search left stop switch only
2
Search right stop switch, then search left stop switch
3
Search right stop switch, then search left stop switch from both sides
4
Search left stop switch from both sides
5
Search home switch in negative direction, reverse the direction when left stop switch reached
6
Search home switch in positive direction, reverse the direction when right stop switch reached
7
Search home switch in positive direction, ignore end switches
8
Search home switch in negative direction, ignore end switches
Adding 128 to these values reverses the polarity of the home switch input.
The next two pages show all possible modes of reference search according to the specific commands on
top of each drawing.