Prescale Value; Auto-Zero Time (Avt); Startup Time (Stmr); Display Color (Colr) - Omron H7BX Datasheet

■ Explanation of Functions
Settings marked with a star can be performed with the DIP switch.
Tachometer Output Mode (totm) ★
Set the output method for control output based on the OUT1/
OUT2 set value. Upper and lower limit (HI-LO), area (AREA),
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 22.)
Counting Speed (cnts) ★
Set the maximum counting speed (30 Hz/10 kHz) for CP1 input.
If contacts are used for input signals, set the counting speed to
30 Hz. Processing to eliminate chattering is performed for this
setting.
Decimal Point Position (dp)
Decide the decimal point position for the measurement value,
OUT1 set value, and OUT2 set value.
Prescale Value (pscl)
It is possible to display the rate of rotation or the speed of a
device or machine to which the H7BX is mounted by converting
input pulses to a desired unit. If this prescaling function is not
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)

: Prescale value

1. Displaying the Rotation Rate
Display unit
rpm
rps
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 place.
2. Using the formula, set the prescale value to 1/N
60/5 = 12.
2. Displaying the Speed
Display unit
m/min
m/s
N: Number of pulses per revolution
d: Diameter of rotating body (m)
d: Circumference (m)
Note: Incorrectly setting the prescale value will result in
counting errors. Check that the setting has been
performed correctly before using the H7BX.
Average Processing (aug) ★
Flickering display and output chattering can be prevented by
using average processing (simple averaging). 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.
The measurement cycle will be equal to the sampling cycle
(200 ms) multiplied by the average processing setting (i.e., the
number of times). Average processing enables fluctuating input
signals to be displayed stably. Set the optimum number of times
for the application.
Prescale value ( )
1/N 60
1/N
60 =
Prescale value ( )
d 1/N 60
d 1/N
d: Diameter
of rotating
body
Auto-zero Time (avt) ★
It is possible to set the H7BX so that if there is no pulse for a
certain time the display is force-set to 0. This time is called the
auto-zero time. Set the auto-zero time to a time slightly longer
than the 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.

Startup Time (stmr)

In order to prevent undesired output resulting from unstable input
immediately after the power supply is turned ON, it is possible to
prohibit measurement for a set time. This time is called the
startup time.
It can also be used to stop measurement and disable output until
the rotating body reaches the normal rate of rotation, after the
power supply to the H7BX and rotating body are turned ON at
the same time.
Display
Comparison
value
(lower limit)
Power supply
Output (lower limit)
NPN/PNP Input Mode (imod) ★
Select either NPN input (no-voltage input) or PNP input (voltage
input) as the input format. Select an NPN input when using a 2-
wire sensor.
The same setting is used for all external inputs.
For details on input connections, refer to Input Connections on
page 6.

Display Color (colr)

Set the color used for the measurement value.
Control output OFF
red
grn
Measured value displayed
r-g
in red when both control
(See note 1.)
outputs 1 and 2 are OFF.
Measured value displayed
g-r
in green when both control
(See note 2.)
outputs 1 and 2 are OFF.
Note 1. If the tachometer output mode is set to AREA, however, the measured
value is displayed in red when control output 1 is OFF and in green
when control output 1 is ON.
2. If the tachometer output mode is set to AREA, however, the measured
value is displayed in green when control output 1 is OFF and in red
when control output 1 is ON.
Key Protect Level (kypt)
Set the key protect level.
For details, refer to Key Protect Level on page 24.
Multifunction Counter
Startup time
Time
Control output ON
Red (fixed)
Green (fixed)
Measured value displayed in
green when either control output
1 or control output 2 is ON.
Measured value displayed in red
when either control output 1 or
control output 2 is ON.
H7BX
21