MaGoOoDy
Member
hi,
i have a lift station project which consists of 2 pumps working in Lead/lag every 7 days or duty switch cycle when one of the pumps have 200 working Hours more than the other one.
i have almost completed the project when i realized that how could i rely on my timers and counters when the PLC lost the power , how could be sure that the values/Accumulators retain their values when the PLC power up again, exactly i am using retentive timers, counters and some Math functions.
the second question, for calculating the 7 days duty cycle, i am just putting a retentive timer directly on the rung so if the PLC powered up it will keep timing regardless the mode of the HOA switch, is this a proper way to implement this 7 days duty cycle?
and i am wondering how others program the 7 days duty cycle ?
i am using AB 1100 PLC .
i have a lift station project which consists of 2 pumps working in Lead/lag every 7 days or duty switch cycle when one of the pumps have 200 working Hours more than the other one.
i have almost completed the project when i realized that how could i rely on my timers and counters when the PLC lost the power , how could be sure that the values/Accumulators retain their values when the PLC power up again, exactly i am using retentive timers, counters and some Math functions.
the second question, for calculating the 7 days duty cycle, i am just putting a retentive timer directly on the rung so if the PLC powered up it will keep timing regardless the mode of the HOA switch, is this a proper way to implement this 7 days duty cycle?
and i am wondering how others program the 7 days duty cycle ?
i am using AB 1100 PLC .