Short description
A configured time is triggered with a signal at the monitoring input. The output is set when this time has expired.
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Connection |
Description |
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Inout 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). |
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Input En |
En is the monitoring input. LOGO! scans the On Time of this input. |
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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 h to 9999 h, 0 m to 59 m
OT: Accumulated total operating time. An offset start time can be specified in hours and minutes. Q → 0:
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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 threshold trigger: Ax
Analog amplifier: Ax
Analog multiplexer: AQ
Analog ramp: AQ
Mathematic instruction: AQ
PI controller: AQ
Up/Down counter: Cnt
For the 0BA7 and later version devices, you can additionally use the actual values of the following already-programmed functions:
On-delay: Ta
Off-delay: Ta
On-/off-delay: Ta
Retentive on-delay: Ta
Wiping relay(pulse output): Ta
Edge triggered wiping relay: Ta
Asynchronous pulse generator: Ta
Stairway light switch: Ta
Multiple function switch: Ta
Stopwatch: AQ
Analog filter: AQ
Average value: AQ
Max/Min: AQ
Threshold trigger: Fre
You select the required function by the block number.
Timing diagram
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 is retained when you reset the hours counter with a signal at input R. The hours counter OT will be reset to zero with a transition from 0 to 1 at Ral. 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. MN is calculated according to the following formula when reset input R is never enabled: MN = MI - (OT % MI). The % operator provides an integer division remainder.
Example:
MI = 30h, OT = 100h
MN = 30 - (100 % 30)
MN = 30 -10
MN = 20h
In runtime mode, the value OT cannot be preset. If the value for MI is changed, there would be no calculation for the MN. MN would take on the value of MI.
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 retentive.
If the values of the hours counter are lost after a power failure, then select the respective block in your circuit program. Right-click the hours counter and select Block Properties > Parameter. 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. |
Value reset
If you download a circuit program that contains an hours counter function from LOGO!Soft Comfort to a LOGO! 0BA7 or LOGO! 0BA8 Base Module, LOGO!Soft Comfort prompts you whether to continue or not. If you continue with the download, the hours counter value is reset.
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Note
If you copy a circuit program that contains an hours counter function from an SD card to a LOGO! Base Module, the hours counter value is reset with no notification. |