40
H7CX
H7CX
Precautions
!Caution
Do not use the product in locations subject to flammable or ex-
plosive gases. Doing so may result in explosion.
The service life of the output relays depends on the switching
capacity and switching conditions. Consider the actual applica-
tion conditions and use the product within the rated load and
electrical service life. Using the product beyond its service life
may result in contact deposition or burning.
Do not disassemble, repair, or modify the product. Doing so may
result in electric shock, fire, or malfunction.
Do not allow metal objects or conductive wires to enter the prod-
uct. Doing so may result in electric shock, fire, or malfunction.
■
External Power Supply
The capacity of the external power supply is 100 mA at 12 V.
When using a 24 VAC/12 to 24 VDC power supply, reduce the
load with the power supply voltage, as shown in the following dia-
gram (DC power supplies only).
■
Power Supplies
When turning the power ON and OFF, input signal reception is
possible, unstable, or impossible as shown in the diagram below.
Turn the power ON and OFF using a relay with a rated capacity of
10 A minimum to prevent contact deterioration due to inrush cur-
rent caused by turning the power ON and OFF.
Apply the power supply voltage through a relay or switch in such a
way that the voltage reaches a fixed value immediately, otherwise
they may not be reset or a counter error may result.
Be sure that the capacity of the power supply is large enough,
otherwise the counter may not start due to inrush current (approx.
10 A) that may flow for an instant when the counter is turned ON.
Make sure that the fluctuation of the supply voltage is within the
permissible range.
Make sure that the voltage applied is within the specified range,
otherwise the internal elements of the counter may be damaged.
■
Transistor Output
The transistor output of the H7CX is isolated from the internal cir-
cuitry by a photocoupler, so the transistor output can be used as
both NPN and PNP output.
The diode connected to the collector of the output transistor is
used to absorb inverted voltage that is generated when an induc-
tive load is connected to the H7CX.
■
Changing the Set Values
When changing the set value during operation, because the
H7CX uses a constant read-in system, output will turn ON if the
set value is equal to the present value.
■
Operation with a Set Value and Present
Value of 0
If the set value and present value are both 0, output will turn ON.
Output will turn OFF during reset.
■
Using the Prescaling Function
Observe the following points when setting a prescale value.
• Set the set value to a value less than {Maximum countable value
-
Prescale 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
-
1.25).
• If the set value is set to a value greater than this, output will not
turn ON.
Note:
Output will turn ON, however, if a present value overflow
occurs (FFFFFF or FFFF).
• Setting the prescale value incorrectly may result in incorrect
counting operation. Be sure to set the prescale value correctly.
■
DIP Switch Setting
Ensure that the power is turned OFF before changing DIP switch
settings. Changing DIP switch settings with the power turned ON
may result in electric shock due to contact with terminals subject
to high voltages.
■
Power Failure Backup
All data is stored in the EEPROM when there is power failure. The
EEPROM can be overwritten more than 100,000 times. EEPROM
is overwritten when the power is turned OFF or when settings are
changed.
10.8
15
100
20
L
oad cu
rre
nt (m
A
)
Power supply voltage (VDC)
(DC voltage supply only)
200 ms
5 ms
ON
OFF
Power
supply
Input
Impossible
Unstable
Possible
Unstable
Impossible
0 to 1 s
0 to 90 ms
+
+
Power for load
Power for load
Load
Load
NPN output
PNP output
+
Counter
Power for load
Inductive load
