The PLC electric control system is logically controlled by theS7series programmeble controller systern software manufactured by theSiemens, instead of the logical operation of the TKD series relay:users can set the operating parameters and run the image-text displayby the 10,4in color touch panel, which realizes all the potection requirements of the coal mine safe regulations, and it has the followingfunetlons
        1 speed display
        2image-test display by the human-machine interface
        3 speed diegrarn display
        40ve-speed protection
        5 limited speed protectian for ?m
        6invalidaticn protectian for depth indicator
        7 shaft-bxoken protection for encader shaft
        8rcpe-loosen prolectian
        9backup deceleate protection,and alarmng at the poini ofthe decelerate
       10 record for the failue alarmn
       11 outage memoty function
       12 back-up protection for over reel
       13 autcmatic parking at the wellhead
       14 direction automatic lockout and other back up protection

        The dotting signal display and lockout provide conditicns for theautomated running of the electric production, also it can automaticallytest the failure when the hoist is running, and make instructions, thenautomatically list the recards, which is convenient far the record andmaintain at the site, and ensure the equipment running for long time

        This systern software has wan 2 items of the nalional patentand we have got the independence intellectual propetty