6. Function blocks6.1 Manufacturer function blocks6.1.1.3 OT - Operating hours counterGeneraleasyE4 base devices provide 4 operating hours counter func-tion blocks, OT01 through OT04. These function blocks outputminutes and seconds in addition to hours. A comparison with areference value that can be entered makes it possible, forinstance, to signal when maintenance work is due.The counter states are retained even when the device isswitched off.Operating principleThe operating hours counter will run as long as input EN has a state of 1. The operatinghours counter's seconds will be output at SC, the minutes at MN, and the hours at QV.The second and minute values will run from 0 to 59, and the hour values will run from 0to 596,523 h.The operating hours counter features a comparison function. The corresponding ref-erence value needs to be connected to I1. With every call, the value of the operatinghours counter will be compared with the value at I1. The operating hours counter fea-tures a direction input, D_.If the operating hours exceed the reference value at I1 when counting up, function blockoutput Q1 will switch to 1 as long as the number of operating hours is greater than orequal to the reference value.If, on the other hand, the operating hours fall below the reference value at I1 whencounting down, function block output Q1 will switch to 1 until the number of operatinghours is greater than the reference value.The operating hours counter can be preset to any value you want. This value needs tobe connected to SV and applied with a wising edge at SE.The operating hours at QV will not be reset to zero unless reset input RE is activated.An operating mode change between STOP/RUN, supplyvoltage ON/OFF, deleting the program, editing the program,loading a new program: None of these actions will clear theoperating hours counter's actual value.However, operating hours will not be added if the program isnot running.The actual value can only be cleared by using the reset input.188 easyE4 11/18 MN050009 EN www.eaton.com
