Functions of Digital I/O Units
4-4-5
Total ON Time Monitor
Function Overview
Note
The total ON time for each I/O contact can be calculated (unit: s) and
recorded in the Unit. A monitor value can be set in the Unit, and when the total
I/O contact ON time reaches the monitor value, the Connected Device Mainte-
nance Flag in the Status Area is turned ON. (Bit 2 of the Communications
Unit's Status Flags is turned ON.) The Programming Device can be used to
read the status of the Connected Device Maintenance Flag.
• Measured time: 0 to 4,294,967,295 s (stored data: 00000000 to
FFFFFFFF hex)
• Measuring unit: s
Slice I/O Unit
Connected
device
1. The Total ON Time Monitor and Contact Operation Counter cannot be
used at the same time for a single contact. Select the function to be used
in the Detection Mode Area.
2. The Total ON Time Monitor operates when the I/O power is ON only.
3. The Total ON Time Monitor checks approximately every second whether
the connected devices are ON.
If the total ON time is calculated for ON times of less than a second, the
measurement may not be accurate.
■ Measurement for ON Time of 0.5 s:
In Figure 1, the actual ON time is 0.5 s × 3 = 1.5 s. The measurement will be
taken once during this ON time, so the total ON time will be measured as 1 s.
Reading taken approximately every second.
ON
OFF
0.5 s
Figure 1
Recorded in
the Unit
Total ON time
Total ON time
Connected
device
Section 4-4
ON
OFF
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