plc精选简答（PLC select t）.docVIP

plc精选简答（PLC select t） 1, 1985, the International Electrotechnical Commission IEC made the following provisions of PLC: programmable controller is A digital electronic system operation, designed for the application of industrial design environment. 2 SIMATIC S7-200 series PLC data type checking is divided into complete data type checking and data type checking simple data type checking, 3, S7-200 series PLC has a total of 6 high-speed counter, of which only 1 working modes are HSC3 and HSC5 Timer 4, there are three types, including TON, TOF, TONR 5, PLC Chinese: full name: Chinese called the programmable logic controller 6, PLC:: PLC hardware hardware consists of a central processor (CPU), memory, input unit, output unit, communication interface, power expansion interface etc.. 7, the working way of PLC is: PLC works: the cycle scan, centralized input and centralized output way Three command system form 8 S7-200 series PLC is divided into ladder diagram program instruction statement list program, function block diagram of program instructions 9, S7-200 series of PLC data storage between two parts, data storage and data object The three instruction system form 10, S7-200 series PLC:: ladder diagram program instruction statement list program, function block diagram of program instructions 11, the working process of the PLC scan (briefly) Answer: (1) self diagnosis; (2) communication processing (3) scan input 4) program (5) output refresh 12, FOR, two of all instructions instructions between NEXT form a loop body. Data addressing 13, S7-200 series PLC instruction system of the immediate, direct addressing, indirect addressing The output of the 15, PLC usually has three forms: relay output, bidirectional thyristor output transistor output 16, the guiding ideology of state programming? Answer: General SFC programming A. three elements: driving load, transfer conditions, transfer target. Transfer conditions, transfer target two indispensable driving load, depending on the