h7cx-a114-n Omron Corporation, h7cx-a114-n Datasheet - Page 45

• Manufacturer Part Number: h7cx-a114-n
• Description: Multifunction Counter/tachometer
• Manufacturer: Omron Corporation

Explanation of Functions
Basic Functions
Input Mode
The mode can be switched between tachometer mode and AMD-
compatible mode.
Tachometer Mode
Use this mode to measure the pulse frequency (Hz).
AMD-compatible Mode
Use this mode to measure the pulse cycle (s).
Counting Speed
Set the maximum counting speed (30 Hz/10 kHz) for input. If contacts
are used for input signals, set the counting speed to 30 Hz.
Processing to eliminate chattering is performed for this setting.
Output Mode
Set the output method for control output based on the comparison
value.
Upper and lower limit (HI-LO), area (AREA), upper limit (HI), and
lower limit (LO) can be set. For the H7CX-RW@, the upper limit (HI-
HI) and lower limit (LO-LO) can be set. (For details on the operation
of the output modes, refer to Output Mode Settings on page page 49.)
Averaging Method (avgt)
Simple averaging or a moving average can be selected for the
averaging method.
With a moving average, the average measurement value is displayed
every sampling cycle or pulse cycle, in contrast to simple averaging,
for which the average value is displayed for the set number of
samples.
Number of Averaging Times
Flickering display and output chattering can be prevented using
average processing. Average processing can be set to one of four
levels: no average processing, 2 times (i.e., the average of 2
measurement values), 4 times, or 8 times.
For a measurement frequency of 5 Hz or higher using a tachometer,
the average will be equal to the sampling cycle (200 ms) multiplied by
the averaging setting (i.e., the number of times).
For less than 5 Hz, the frequency will be measured when the input
pulse comes. Average processing produces a stable display even for
fluctuating input signals. Set the optimum number of times for the
application.
If AMD-compatible mode is used, the measurement cycle will be
measured when the input pulse is received. The output will change,
however, when the comparison value is exceeded even if averaging
is enabled.
NPN/PNP Input Mode
Select either NPN input (no-voltage input) or PNP input (voltage
input) as the input format. When using a two-wire sensor, select NPN
input.
The same setting is used for all external inputs.
For details on input connections, refer to Input Connections on page
page 40.
Cycle (s)
Advanced Functions
Decimal Point Position (dp)
Decide the decimal point position for the measurement value and
comparison value.
Prescale Value (pscl)
It is possible to display the rate of rotation or the speed of a device or
machine to which the H7CX is mounted by converting input pulses to
a desired unit.
If the default prescaling value (1,000) is used, the input frequency
(Hz) will be displayed.
The relationship between display and input is determined by the
following equation. Set the prescale value according to the unit to be
displayed.
Displayed value = f
f: Input pulse frequency (number of pulses in 1 second)
(1) Displaying Rotation Rate
N: Number of pulses per revolution
Example: In order to display the rate of rotation for a machine that
outputs 5 pulses per revolution in the form @@.@ rpm:
1. Set the decimal point position to 1 decimal places.
2. Using the formula, set the prescale value ( ) to
1/N
(2) Displaying Speed
N: Number of pulses per revolution
d: Diameter of rotating body (m)
Auto-zero Time (auto0)
It is possible to make the settings so that the frequency will be force-
set to 0 if there is no pulse for a specified period of time. This time is
called the auto-zero time.
• Observe the following points when
d: Circumference (m)
Note: If the prescale value setting is incorrect, a counting error will
: Prescale value
Note: Set the auto-zero time to a time slightly longer than the
setting a prescale value.
Set the set value to a value less than {Maximum countable value
Example: If the prescale value is 1.25 and the counting range is
0.000 to 999.999, set the set value to a value less than 998.749
(= 999.999
If the set value is set to a value greater than this, output will not turn
ON.
Prescale value}.
60 = 60/5 = 12.
occur. Check that the settings are correct before using this
function.
Display unit
Display unit
estimated interval between input pulses. It will not be
possible to make accurate measurements if the auto-zero
time is set to a time shorter than the input pulse cycle.
Setting a time that is too long may also result in problems,
such as a time-lag between rotation stopping and the
alarm turning ON.
m/min
rpm
m/s
rps
1.25).
Prescale value ( )
Prescale value ( )
d
1/N
d
H7CX-R@-N
1/N
1/N
1/N
60
60
d: Diameter
of rotating
body (m)
45