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

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Pulse Outputs
Section 5-3
Procedure Make the following settings in the PLC Setup.
Pulse Output 0 to 3
Restrictions The following restrictions apply when using S-curve acceleration/deceleration.
Starting Frequency
The starting frequency must be 100 Hz or greater. If the starting frequency is
set to less than 100 Hz, it will automatically be increased to 100 Hz if S-curve
acceleration/deceleration is set.
Target Frequency
S-curve acceleration/deceleration will not be performed if the target frequency
is less than 100 Hz.
Precautions when
using the Pulse
Output Function
The CP1H CPU Unit’s pulse output frequency is determined by dividing the
source clock frequency by an integer ratio. (The source clock frequency for
ports 0 and 1 is 20 MHz and the frequency for ports 2 and 3 is 16.4 MHz.)
Consequently, there may be a slight difference between the set frequency and
the actual frequency, and that difference increases as the frequency
increases. The actual frequency can be calculated from the following equa-
tions.
Pulse Output System
Speed Curve Trapezium When a pulse output is executed with accelera-
tion/deceleration, this setting determines
whether the acceleration/deceleration rate is lin-
ear (trapezium) or S-shaped.
S-shaped
50 Hz
100 Hz
Automatically
increased
to 100 Hz.
Pulse frequency
Time
50 Hz
No
acceleration/deceleration
Time
Pulse frequency
Frequency
divider
Output pulses (actual frequency)
Integer dividing ratio calculated
from user's set frequency
Source
clock
16.4 or
20 MHz