Omron CPM1 - Page 360

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Special Instructions Section 5-26
In independent mode, the number of pulses that have been output to ports 1
and 2 are contained in IR 236 and 237 (port 1) and IR 238 and IR 239 (port 2).
In continuous mode, pulses will be output until the INI(61) instruction is exe-
cuted with C=003 or SPED(64) is executed again with F=0000. If the direction
(CW or CCW) is not specified when outputting from port 1 or 2, the pulses will
be CW.
Pulse Frequency (F) The value of F sets the pulse frequency in units of 10 Hz, as shown below.
Setting F to 0000 will stop the pulse output at the specified location.
Precaution Regarding Pulse Output
The pulse frequency output from the CQM1-CPU43-EV1 is generated by
dividing the 500-kHz basic clock by a dividing unit of an integer value, which
results in a difference between the set frequency and actual frequency. Refer
to the following equation for calculating an actual frequency.
Set Frequency: Output frequency set in the instruction by the user
Dividing Unit: An integer set in the dividing circuit to generate an output
pulse of the set frequency
Actual Frequency: Output pulse frequency actually output from the dividing
circuit
Equation:
Actual frequency (KHz) = 500 (KHz)/INT (500 (kHz)/Set frequency (kHz))
INT: Function for obtaining an integer value
INT (500/Set frequency): Dividing unit
The difference between the set frequency and actual frequency becomes
larger as the frequency becomes higher.
Example:
Leftmost 4 digits Rightmost 4 digits
IR 237 IR 236Port 1 pulse output PV:
IR 239 IR 238Port 2 pulse output PV:
Output location Possible values of F
Port 1 or 2 0000 (stops pulse output) or 0001 to 5000 (10 Hz to 50 kHz)
Output bits 0000 (stops pulse output) or 0002 to 0100 (20 Hz to 1 kHz)
Set frequency (kHz) Actual frequency (kHz)
45.46 to 50.00 50.00
41.67 to 45.45 45.45
38.47 to 41.66 41.67
::
31.26 to 33.33 33.33
29.42 to 31.25 31.25
27.78 to 29.41 29.41
::
20.01 to 20.83 20.83
19.24 to 20.00 20.00
The dividing unit is set based on
the frequency set by the user.
500 kHz
Pulse-
generating
clock
Dividing circuit
Output pulse
(actual frequency)