Omron CP1H CPU UNITS - PROGRAMMING 05-2007, Operation Manual

Page: 288 / 788

254
Pulse Outputs
Section 5-3
2. Changing the Pulse Output PV
When you want to set the current position as the origin, execute INI(880)
to reset the pulse output PV to 0.
The origin location can be determined after using either method.
The CP1H CPU Units are also equipped with the origin return function, which
can be executed to return the system to the origin after the origin location has
been determined by one of the methods above.
• Origin Return
If the motor is stopped, ORG(889) can be executed to perform an origin
return operation that moves the motor back to the origin position. The ori-
gin position must be determined in advance by performing an origin
search or changing the pulse output PV.
Note The motor can be moved even if the origin position has not been determined,
but positioning operations will be limited as follows:
• Origin return: Cannot be used.
• Positioning with absolute pulse specification: Cannot be used.
• Positioning with relative pulse specification: Outputs the specified number
of pulses after setting the current position to 0.
5-3-5-1 Origin Search
When ORG(889) executes an origin search, it outputs pulses to actually move
the motor and determines the origin position using the input signals that indi-
cate the origin proximity and origin positions.
The input signals that indicate the origin position can be received from the
servomotor's built-in phase-Z signal or external sensors such as photoelectric
sensors, proximity sensors, or limit switches.
Several origin search patterns can be selected.
In the following example, the motor is started at a specified speed, acceler-
ated to the origin search high speed, and run at that speed until the origin
proximity position is detected. After the Origin Proximity Input is detected, the
motor is decelerated to the origin search low speed and run at that speed until
the origin position is detected. The motor is stopped at the origin position.
Pulse frequency
Origin search
initial speed
Origin search
acceleration rate
Origin search
high speed
Deceleration
point
Origin search
deceleration rate
Origin search
proximity speed
Start
Execution of ORG(889)
Decelerate from high to low speed.
Indicated by the Origin
Proximity Input Signal
Stop
Indicated by the
Origin Input Signal
Time