Omron H5CX Manual page 48

Precautions for Correct Use
Power Supplies
Turn the power ON and OFF using a relay with a rated capacity of 10
A minimum to prevent contact deterioration due to inrush current
caused by turning the power ON and OFF.
Be sure that the capacity of the power supply is large enough,
otherwise the Timer may not start due to inrush current that may flow
for an instant when the Timer is turned on.
When turning the power ON and OFF, input signal reception is
possible, unstable, or impossible as shown in the diagram below.
Power
ON
supply
OFF
0 to 50 ms
200 ms
Input Impossible
Unstable
Timer Control with Power Start
To allow for the startup time of peripheral devices (sensors, etc.), the
H5CX starts timing operation between 200 ms to 250 ms after power
is turned ON. For this reason, in operations where timing starts from
power ON, the time display will actually start from 250 ms. If the set
value is 249 ms or less, the time until output turns ON will be a fixed
value between 200 and 250. (Normal operation is possible for set
value of 250 ms or more.) In applications where a set value of
249 ms or less is required, use start timing with signal input.
When the H5CX is used with power start in F mode or F-1 mode (i.e.,
accumulative operation with output on hold), there will be a timer
error (approximately 100 ms each time the H5CX is turned ON) due
to the characteristics of the internal circuitry. Use the H5CX with
signal start if timer accuracy is required.
Transistor Output
The transistor output of the H5CX is insulated from the internal
circuitry by a photocoupler, so the transistor output can be used as
both NPN and PNP output.
NPN Output PNP Output
Load Load
+
Power for load Power for load
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 H5CX.
Timer
Inductive load
+
Power for load
48
Digital Timer
0 to 500 ms
5 ms
Possible Unstable Impossible
+
H5CX
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.
Minimum reset signal width
1 ms
20 ms
Power Failure Backup
All data is stored in the EEPROM when there is a power failure. The
EEPROM can be overwritten more than 100,000 times.
Operating mode
A-3, b-1, F, F-1 mode When power is turned OFF.
Other mode When settings are changed.
Conformance to EN/IEC
Standards
There is no insulation between power supply and input terminals
(except for H5CX-A11/-A11S).
Basic insulation between power supply and output terminals, and
between input terminals and output terminals.
When double insulation or reinforced insulation is required, apply
double insulation or reinforced insulation defined in IEC 60664 that is
suitable for the maximum operating voltage with clearances or solid
insulation.
(Reference value)
Output delay time
0.8 to 1.2 ms
15 to 25 ms
Overwriting timing