Datasheet

Safety Precautions H7CX Series 61
Safety Precautions (H7CX-A)
■ Precautions for Safe Use
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.
■ Precautions for Correct Use
Power Supplies
When turning the power ON and OFF, input signal reception is
possible, unstable, or impossible as shown in the diagram below.
Transistor Output
The transistor output of the H7CX is isolated from the internal
circuitry 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 inductive load
is connected to the H7CX.
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.
Response Delay Time When Resetting
(Transistor Output)
The following table shows the delay from when the reset signal is
input until the output is turned OFF.
(Reference values)
Output Delay Time
The following table shows the delay from when the present value
passes the set value until the output is produced.
Actual measurements in N and K-2 modes.
(Reference values)
Note: The above times may vary slightly depending on the mode or
operating conditions.
Maximum Counting Speed for Batch
Counter
The maximum counting speed for batch counter operation is 5 kHz.
The batch counter counts the number of times the count reaches the
set value.
200 ms 5 ms
ON
OFF
Input Impossible
Unstable
Possible
Unstable
Impossible
0 to 1 s0 to 90 ms
Power
supply
++
Power for load Power for load
Load Load
NPN output PNP output
+
Counter
Power for load
Inductive load
Minimum reset signal width Output delay time
1 ms 0.8 to 1.2 ms
20 ms 15 to 25 ms
Control output type Maximum counting
speed
Output delay time
Contact output 30 Hz 16.5 to 24.0 ms
5 kHz 3.7 to 5.6 ms
Transistor output 30 Hz 12.0 to 20.0 ms
5 kHz 0.2 to 0.55 ms