Omron SYSMAC CJ1W-AD04U, Руководство по эксплуатации

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4
Features and Functions Section 1-1
The following example shows the operation of the high limit alarm output.
Input Error Detection An error input can be detected if the input signal significantly exceeds the high
or low limit.
Note With thermocouple and platinum resistance thermometer inputs, an input
error is detected if the temperature exceeds the high or low limit of the sensor
range by 20
°
C or 20
°
F.
With voltage and current inputs, an error is detected only for the following val-
ues in the 1 to 5 V and 4 to 20 mA ranges:
• 1 to 5 V range: Converted AD value < 0.3 V
• 4 to 20 mA range: Converted AD value < 1.2 mA
Either the high or low direction can be specified for the detection of a discon-
nection.
The allowable range limits are as follows:
• Temperature Input
Upper limit: Upper limit of temperature range +20
°
C or +20
°
F
Lower limit: Lower limit of temperature range
−
20°C or
−
20
°
F
• Voltage/Current Input
Upper limit: 105%
Lower limit:
−
5%
Note Sensor error detection is effective only when the input type is set to thermo-
couple input, platinum resistance thermometer input, 1 to 5 V input, or 4 to
20 mA input. The Sensor Error Flag will be turned ON if there is no input sig-
nal from the thermocouple input, platinum resistance thermometer input, 1 to
5 V input, or 4 to 20 mA input.
Detection of Cold
Junction Sensor Errors If the Unit’s built-in cold junction sensor fails, the Cold Junction Sensor Error
Flag will be turned ON to indicate the error.
Zero/Span Adjustment The zero point and span point can be adjusted for a process value.
The zero adjustment offsets the line plotting values before and after adjust-
ment parallel to the original line. The span adjustment changes the slope of
the line (i.e., the gain) around the minimum value in the range.
Time
Hysteresis
ON delay time
High limit alarm (H)
Process value input
Alarm output (H)
Universal Input Unit
Disconnection
Sensor
Error Flag
CPU Unit
ON
High/low designation:
high or low