Filter
Top Products
187
Pulse Outputs Section 7-6
The PULS(886) instruction (Electronic Cam Control) can be used to imme-
diately change the pulse output value for absolute positioning or the pulse
output frequency for speed control in response to the high-speed counter
PV (e.g., for a rotational angle). This feature allows the Motion Control
Module to perform electronic cam operation using simple linear approxi-
mation of a curve (for position or speed control based on the cam angle).
By setting a constant cycle time, the high-speed counter PV is read at reg-
ular intervals. The PULS(886) (Electronic Cam Control) instruction is exe-
cuted immediately after reading the high-speed counter PV in order to
determine the new target position for that cycle.
With the PULS(886) instruction (Electronic Cam Control), the target posi-
tion or pulse output frequency (speed) can be changed by executing an-
other instruction to change the target position or output frequency while the
PULS(886) instruction is being executed. Consequently, position and
speed control can be performed while outputting pulses, which is not pos-
sible with the PULS(886) + SPED(885) and PULS(886) + ACC(888) in-
struction combinations. This capability allows the target position or pulse
output frequency (speed) to be changed in steps at high-speed in re-
sponse to changes in the pulse input PV. In addition, the pulse input PV
can be processed with operations such as basic arithmetic operations and
the result can be used for the target position or pulse output frequency
(speed).
Note The pulse output direction is selected automatically based on the
relationship between the present position (pulse output PV) and
target position.
Note Speed control can be performed on a virtual axis by generating a virtual axis
position (internal pulse count) with the AXIS instruction, processing that value
with arithmetic operations or the APR instruction, and changing the target
position or speed with the PULS(886) instruction. Refer to 7-8-4 Application
Example for details.
Trapezoidal Pulse Output with Acceleration/Deceleration (PLS2(887))
This procedure shows how to use PLS2(887) to generate a pulse output with
trapezoidal acceleration and deceleration. The number of output pulses can-
not be changed during positioning.
1,2,3... 1. Determine pulse output port.
Pulse input PV
Pulse output PV (absolute position)
Time
PULS instruction execution
(Changes target position and speed.
)
Target position
Time
Execution with constant
cycle time
PULS (Electronic Cam
Mode) is executed in the
program with changed
target position and speed.