With PLC implementation produces process automata
- source:NEWRGY CNC Machining
Circuit Diagram, flow Chart, ladder Diagram And Coding Chart Are Given.
Key Words:PLC, process Control, design, because use traditional relay to control,Application 1 design asks some production process is former, wiring complex, bulk degree of bigger, more cumbersome, automation very not tall, function very not perfect, reliability is very not high also, so the requirement converts can make up Cheng controller to undertake controlling. After improving, its produce a process to control flow sketch map to see a picture 1. The capacity of B of A of the canister in the graph, canister is equal and the half of capacity of D of the C that it is coal tub, canister. The requirement parts solution A and solution B by pump 1 with pump 2 in adding coal tub A and coal tub B, 60 ℃ heat solution B after coal tub B is full, use pump next 3 with pump the solution in 4 canister A and coal tub B joins coal tub C entirely in with 1 mix than the scale of 1, should continue after coal tub C is replete 60 seconds have mix sufficient chemical reaction, next by pump all by filter sends the finished product in 5 canister C in D of finished product canister, finished product of 6 whole canister smokes pump of the open after coal tub D is replete entirely. Begin then new the loop of one cycle. 2 pairs of analysises that design the job 2.
The 1 I/O that decides PLC place needs first the requirement narrates before several basises a few output carry under knowable PC need: The output of beater of a the output end of heater of a the 6 output end that dominates 6 pump respectively, control, control is carried, gross need outputs end 8 times. The input signal end that PC place needs has: 1 can detect whether to already heat the temperature sensor of 60 ℃ , graph 4 medium T E represent temperature (Temperature) sensor, every canister whether full already, empty already also need sensor, graph what 4 medium AF, BF, CF, DF is 4 canister respectively is full already (Full) sensor, e of AE, B, CE, DE is 4 canister respectively is empty already (Empty) sensor, such altogether need 9 inputs to carry. Classics analysis is knowable, in controlling a process, coal tub D is full already sensor DF can use coal tub C CE replaces empty already sensor, can omit accordingly sensor DF, need 8 inputs to carry only so can. Should choose an input to nod so several ≥ 8, output nods a several ≥ the PLC of 8. 2.
The choice that Chu Qirong of 2 users program measures is analysed by above knowable, this system does not need imitate to measure commutation and memory, need 6 1 switch to measure control only, because this can press the following and formulary estimation: 8 =1 of * of gross of I/O of quantity of switch of ≥ of memory word number 8 =148 3 PLC of 6 * the choice of model is analysed according to above, should choose an input to nod a several ≥ 8, output nods a several ≥ 8, memory word counts ≥ the PLC of 148. Do not have special requirement to the scanning speed of PLC and other respect. The model that we choose is ohmic dragon company (the C20P of OMRON) . The leader that C20P can write Cheng controller (main unit) 12 inputs are nodded (8 0000"0011) , output are nodded (capacity of 0500"0507) , process designing is 1194 addresses, timer / tally 48 (TIM00"TIM47) , additionally still auxiliary relay waits. But direct drive electromotor, also can control the load with very great power through relay or contactor. The design of program of 5 echelon plan expresses the allocation of 4I/O contact and hookup of P L C 2 gave out the corresponding relation of actual condition and sensor and process designing component, when echelon pursues, the analysis can be offerred contrast. Graph 3 it is flow chart of pair of each component pilot, graph 4 it is echelon plan program. 6 instructions express a program CNC Milling CNC Machining