Software Limits; Overview; Procedure For Using Software Limits - Omron CJ1W-NC271 - 12-2009 Operation Manual

Software Limits

10-8 Software Limits

10-8-1 Overview

10-8-2 Procedure for Using Software Limits

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To prevent or reduce damage to external devices due to unexpected position-
ing operations when there is a malfunction, in addition to the forward rotation
and reverse rotation limit input signals, the PCU also has a function that mon-
itors positioning at a software level. This function is called the "software limit"
function.
The range in which the software limit function monitors the position is deter-
mined by the values of two settings: the forward software limit and the reverse
software limit. Normally, positioning is only possible within the range deter-
mined by these software limit settings. The relationship between the forward
rotation and reverse rotation limit input signals, the software limits, and the
mechanical stoppers used in the system is shown below.
Reverse software limit
Reverse rotation limit input signal
Mechanical stopper
The software limit function is enabled if an origin has been established (i.e.,
the No Origin Flag is OFF). The software limit function is disabled when the
origin has not been established.
When the Servo Drive power is turned ON, the PCU's present position is set
to 0, and the origin is not established. RELATIVE MOVEMENT can be exe-
cuted under these conditions, but the positioning range (present position
range possible for positioning) will be −2,147,483,648 to 2,147,483,647 (com-
mand units), and the present position will be refreshed by adding the travel
distance without an established origin.
If RELATIVE MOVEMENT is executed using a position command value that
exceeds the positioning range, a Position Designation Error (error code: 3060)
will occur when the command is executed.
When a command such as JOG continues to be executed, the present posi-
tion will be repeated between −2,147,483,648 and 2,147,483,647 (command
units). (Refer to 7-3 Coordinate System and Present Position.)
The PCU uses the Servo Drive's software limit function. The Servo Parame-
ters for software limits must be set to enable the software limit function. After
setting the Servo Parameters, the software limit function is enabled by execut-
ing ORIGIN SEARCH and PRESENT POSITION PRESET, or detecting the
origin using the absolute encoder.
Software level operating range
Electrical level operating range
Mechanical level operating range
Section 10-8
Forward software limit
Forward rotation limit input signal
Mechanical stopper