7 Before Starting Positioning Operation
84
FX
3U
-20SSC-H Positioning Block User's Manual
7.3 Handling the Forward Rotation Limit and Reverse Rotation Limit
7.3.3
Software limit
This operation limit is based on the 0 address that becomes valid after a mechanical zero return.
Specify each software limit in positioning parameters at addresses so that activation is before forward rotation
limit 1 and reverse rotation limit 1 connected with the PLC.
→
For sudden stop operation performed when the software limit turns ON, refer to Section 7.5
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For parameters, control data and monitor data, refer to Chapter 11
*1.
However, set the value within -2,147,483,648 to 2,147,483,647 PLS in converted pulse data.
Refer to the section shown below for details on the user units and converted pulse data.
→
Refer to Section 7.10
Conditions for validating the software limit
• Specify the software limit so that the following condition is satisfied.
Large software limit > small software limit
• State with active zero return complete flag
(After execution of mechanical zero return and completion of positioning at the zero-point, or in an absolute
position detection system where the current value is established)
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For details of the status information, refer to Subsection 11.3.17
Note
To refrain from using the software limit, specify the software limit settings as shown below.
• Software limit (upper) = Software limit (lower)
• Software limit (upper) < Software limit (lower)
Cautions for use of software limit
1) The software limit is invalid under the following control situations.
- Mechanical zero return operation
- Current value change
- Ring counter setting (Ver.1.10 or later)
2) The limit error of the software limit is changed at the starting and end points of the operation. Therefore
the specified upper or lower software limit may be exceeded in circular interpolation control.
In this case, deceleration does not occur even if the software limit is exceeded.
If there is a possibility of overshoot beyond the software limit, install an external limit switch.
BFM Number
Description
X-axis
Y-axis
Software limit (upper)
BFM #14035,
#14034
BFM #14235,
#14234
Sets the software limit (upper)
Setting range: -2,147,483,648 to 2,147,483,647 (user unit)
*1
Software limit (lower)
BFM #14037,
#14036
BFM #14237,
#14236
Sets the software limit (lower)
Setting range: -2,147,483,648 to 2,147,483,647 (user unit)
*1
BFM Number
Description
X-axis
Y-axis
Status
information
Zero return
complete
BFM #28 b3
BFM #128 b3
Turns ON upon completion of mechanical zero return operation, or
when the current position is established by the absolute position
detection system.
Turns OFF at OFF-to-ON transition of a mechanical zero return
command, at power-off (reset), or when an absolute position is lost by
the absolute position detection system.
Y-axis
Y-axis stroke
limit
Deceleration does not occur.
Arc address
Starting point address
End point address
X-axis
