Omron SYSMAC CJ Series, Руководство по эксплуатации

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How-to’s Section 5-1
300
• Origin search using encoder reference pulse "Zero Mark".
• Static origin search, forcing a position from a user reference.
• Static origin search, forcing a position from an absolute encoder.
The figure shows a general origin search scenario. This simple origin search
sequence has 3 steps:
1 Search for a signal.
2 Search for another signal.
3 Move the axis to a predefined position.
It is important to note that, before any homing procedure is executed, it is
necessary to set the axis parameters
UNITS , REP_DIST and REP_OPTION ,
and Servo Driver parameters Pn202, Pn203 and Pn205 properly and in
accordance with the mechanical system and desired measurement units used
in programming. Those parameters have influence to the origin search,
especially if an absolute encoder is used. For more information on setting
these parameters, see section 5-1-2.
5-1-5-1 Absolute switch origin search plus limit switches
The origin search function is performed by searching for an external limit
switch that is positioned absolutely and the position of which defines the origin
position. The example for this homing procedure is shown in the figure.
ON min. limit switch
origin limit switch
moving part
max. limit switch
encoder
OFF
ON OFF OFF
ON OFF
Note For safety reasons, limit switches are normally closed. For this reason, in this figure and
in the following figures in this section, the low signal level is indicated as ON, and the
high signal level is indicated as OFF.
ON OFF OFF
min. limit switch
origin limit switch
moving part
max. limit switch
ON OFF ON OFF