Pulse Outputs

Section 7-6

Note The pulse output can be stopped by executing ACC(888) with a deceleration target frequency of 0. However, since the pulse output cannot be stopped at the correct number of pulses, the deceleration target frequency should not be set to 0 if it is necessary to output a precise number of pulses.

Specified number of pulses

Speed reaches 0 while the remaining

reached before speed reaches 0.

number of pulses is 0 or more.

Speed

Speed

(frequency)

(frequency)

0

 

Time

0

Time

 

 

 

 

 

At this point, the actual number of output

 

At this point, the actual number of output pulses

 

pulses equals the preset number of pulses.

 

may not equal the preset number of pulses.

 

 

 

 

To be sure that the actual number of output

 

 

 

 

pulses equals the specified number of pulses,

 

 

 

 

set the Module so that the speed is greater

 

 

 

 

than 0 (e.g., the starting frequency) when the

 

 

 

 

specified number of pulses have been output.

Absolute Positioning with Continually Changing Target Position

Pulse output target frequency in D00000 and D00001 (BCD)

This example performs absolute positioning (Electronic Cam Control) using a single-phase pulse output without acceleration/deceleration, and the target position is updated every cycle. This function relies on a constant cycle time, in which the ladder program is executed every 2 ms, and positioning is per- formed using a target value that is changed every cycle according to the high-speed counter PV.

The pulse output is controlled by the target position, which is calculated repeatedly from the high-speed counter PV. The target position is calculated, so the APR instruction can be used for linear approximation.

4,000

0

 

 

 

 

 

 

High-speed

 

 

 

 

 

 

200

400

600

800

999

Counter PV (BCD)

 

The high-speed counter is set for circular operation with a circular value of 999 BCD.

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Image 214
Omron FQM1-MMA21, FQM1-CM001, FQM1-MMP21 operation manual Number of pulses is 0 or more, Speed