Short description
A configured time is triggered with a signal at the monitoring input. The output is set when this time has expired.
Connection |
Description |
Input R |
A positive edge (0 to 1 transition) at input R resets output Q and sets a configured value MI at the counter for the duration of the time-to-go (MN). |
Input En |
En is the monitoring input. LOGO! scans the On Time of this input. |
Input Ral |
A positive edge at input Ral (Reset all) resets the hours counter (OT) and the output, and sets the time-to-go value (MN) to the configured maintenance interval (MI):
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Parameter |
MI: Maintenance interval to be specified in units of hours and minutes Range of values: 0000...9999 h, 0…59 m OT: Accumulated total operating time. An offset start time can be specified in hours and minutes. Q
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Output Q |
The output is set when the time-to-go MN = 0. The output is reset:
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Parameter MI
The maintenance interval MI can be provided by the actual value of another already-programmed function:
Analog comparator: Ax – Ay
Analog trigger: Ax
Analog amplifier: Ax
Analog multiplexer: AQ
Analog ramp: AQ
Analog math: AQ
PI controller: AQ
Up/Down counter: Cnt
You select the required function by the block number.
Timing diagram
MI = Configured time interval
MN = Time-to-go
OT = Total time expired since the last 1 signal at the Ral input
These values are always retentive.
Description of the function
The hours counter monitors input En. As long as the status at this input is 1, LOGO! calculates the expired time and the time-to-go MN. LOGO! displays these times when set to configuration mode. The output is set to 1 when the time-to-go is equal to zero.
You reset output Q and the time-to-go counter to the specified value MI with a signal at input R. The operation hour counter OT remains unaffected.
You reset output Q and the time-to-go counter to the specified value MI with a signal at input Ral. The operation hour counter OT is reset to 0.
Depending on your configuration of the Q parameter, the output is either reset with a reset signal at input R or Ral ("Q R"), or when the reset signal is 1 or the En signal is 0 ("Q
R+En").
Viewing the MI, MN and OT values
In LOGO!Soft Comfort you can fetch the hours counter via the Tools -> Transfer: Hours counter menu command.
Limit value of OT
The value of the operating hours in OT are retained when you reset the hours counter with a signal at input R. The hours counter OT continues the count as long as En = 1, irrespective of the status at the reset input R. The counter limit of OT is 99999 h. The hours counter stops when it reaches this value.
In programming mode, you can set the initial value of OT. The counter starts operation at any value other than zero. MN is automatically calculated at the START, based on the MI and OT values.
Example: MI = 100, OT = 130, the result is MN = 70
Parameter preset
In LOGO!Soft Comfort, you can define MI and an OT start value.
You determine that Q does not depend on En by selecting the corresponding check box.
Retentivity with the hours counter
The hours counter in the LOGO! is generally retentive.
However, if the values of the hours counter are lost after a power failure, then select the respective block in your circuit program. Right-click on the hours counter and select Block Properties > Parameters. The option Retentivity must be activated and unchangeable (grayed out).
If the Retentivity option is not available, then delete the block and insert a new special function hours counter at the same position.
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0BA0-0BA5: The maintenance interval (MI) and the start time for the operating time (OT) were in units of hours. These values could not be provided by another function prior to the 0BA6 device series. |