Omron FQM1-CM001, FQM1-MMA21, FQM1-MMP21 operation manual 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.

Pulse input PV

Time

Execution with constant cycle time

	PULS instruction execution
Pulse output PV (absolute position)	(Changes target position and speed.)
	Target position

PULS (Electronic Cam Mode) is executed in the program with changed target position and speed.

Time

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.

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