Omron FQM1-MMA21 Pulse Inputs, Section, Monitoring a High-speedCounter’s Frequency Mode

Pulse Inputs Section 7-5

Note

Monitoring a High-speed Counter’s Frequency (Mode 2)

Note

High-speed Counter Movement (Mode 1) Specifications

Item	Specifications
Applicable pulse	Either pulse 1 (high-speed counter 1) or pulse 2 (high-speed
input	counter 2) can be used.
Displayable move-	0000 0000 to FFFF FFFF
ment	Note The software can generate the range of values shown
	above, but some hardware may not be able to display
	the full range due to input limitations.
Sampling time	Can be set to the cycle time or a fixed time between 1 and
	9,999 ms.
Operating conditions	In the System Setup, set the pulse input’s counter data display
	to counter movements (mode 1) and specify the sampling
	time.

(1)When using mode 1 with a circular counter, set the maximum circular val- ue to 10 or higher.

(2)In mode 1, the Motion Control Module outputs the change as the differ- ence in the count measured each sampling period. The output change varies, so determine how to manage the output value in the user program when the counter is reset or the INI(880) instruction is executed to change the PV during sampling.

Mode 2 is supported by high-speed counter 1 only.

This function monitors the input pulse’s frequency from the high-speed counter movement value. The frequency is stored in A604 and A605. Status Flag A608.06 can be checked to determine whether or not the frequency is being measured.

(1)The frequency value stored in the Auxiliary Area is refreshed during the Motion Control Module’s I/O refreshing.

(2)The frequency measurement can be performed only with high-speed counter 1. The frequency cannot be measured with high-speed counter 2.

(3)When measurement is started, the measurement direction (A610.03) must be specified to match the direction of the input pulses being mea- sured.

Word	Bits	Function	Details
A604 and	00 to 15	High-speed Counter 1	Contains the frequency measure-
A605		Monitor Data	ment.
			The frequency calculated from the
			high-speed counter PV is stored in
			8-digit hexadecimal (0000 0000 to
			0007 A120 hex = 0 to 500 kHz).
A608	06	High-speed Counter 1	Measuring Flag
		Status Flag	OFF: The high-speed counter fre-
			quency measurement opera-
			tion is stopped.
			ON: The high-speed counter fre-
			quency is being measured.

The pulse input’s counter data display must be set to frequency measurement (mode 2) in the System Setup in advance.

System Setup	Function	Details
Pulse Input Tab	Specifies the counter 1 mea-	2 hex: Frequency (mode 2)
Page	surement mode.
Counter data display

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