【正文】 output termination perceptual load, must in the load both sides parallel impact blanker or the diode, diode39。s design 1. power source return route The PLC power supply is generally AC85240V (also has DC24V), adapts the power source scope to be wide, but for the antijamming, should install the power source to purify the part (for example power source filter, 1:1 insulating transformer and so on) on DC24V power source39。s steady operation is very important. 3. The storage capacity and the instruction carry out the speed are the PLC shaping important targets, generally the reserves is bigger, the speed quicker PLC price to be higher, although overseas various factories product more or less the same, but also has certain difference. 4. “COM choice, different PLC product, it COM a quantity is dissimilar, some COM belt 8 output spots, some belt 4 output spots, also has the belt 1 or 2 output spot. When the load type are many, and the electric current is big time, uses one COM a belt 12 output product, when the load type minority quantity are many, uses one COM a belt 48 output product. 5. Because each Manufacturer39。s selecting and purchasing: in the present market39。s CPU instructions with stepbystep process to store the address of the program counter, running in the process, each step in the implementation of the automatic counter plus 1, stepbystep process from the start (zerostep number), followed by the final step to the implementation of the (usually END mand), and then return to start stepbystep cycle of operation. Each PLC pleted a cycle of the time required for the operation known as a scanning cycle. Different models of the PLC, scanning cycle to cycle in a microsecond between the scores of microseconds. PLC ladder program used in calculating logic, to show the advantages of quick, microsecond in the order of magnitude, calculating logic 1K procedures less than 1 ms. It all have input as a switch to handle the volume, 16bit (also 32bit) for a simulated traffic. PLC largescale use of a CPU to plete the simulation of the amount of puting. The results sent to the PLC same I / O points system, with PLC than DCS, the cost should be lower (about 40% of the province to around). PLC special operation did not stop it with software and hardware are mon, so maintenance costs much lower than the DCS. One of the PLC controller, you can receive thousands of I / O points (up to more than 8000 I / O). If the object is a chain of equipment, small loop, the PLC to adopt more appropriate. As a result of General PLC control software in the design of management information systems, to be easier. Over the past 10 years, with the PLC to lower prices and growing user demand, a growing number of small and mediumsized equipment to start using PLC control, PLC in China grew rapidly. With China39。Foreign Language Translation 1 At present,the main control way in automation field are rlay control,microputer control and PLC control. Compared with the relay control system and the microputer control systerm,the PLC control systerm has a series of advantages,sush as little work load of designing,installing,wiring and debugging, short cycle of development of working environment and convenient maintenance. Meanwhile, the relay control systerm has already been few used on the machine control systerm is inferior in ability of antiinterference, high in requirement of working environment and long in desigong and developing cycle of the control systerm. So its application has being on deining trnd in the automation conrol field by year. The electrical control system of z3040 Radial arm drill has many defects such as plex circuit, high failure rate, large maintenance workload, poor reliability and flexibility. This paper introduces the z3040 Radial arm drill relay contact analog control system reformation with PLC to guarantee the rapidity, accuracy and rationality of electric control system. It satisfied real production demand and enhance the economic benefit. The original was introduced initial controller of programmable distinguishing feature and performance. Analyses on z3040’s Radial arm drill technique property and the work cycle distance travelled by a stream of water base, expounded the initial controller of application ES’s set programmable carrying on the technological transformation system design to such, and finish e out the control procedure trapezium picture. What is a PLC control system? Since the 1960s the United States to launch programmable logic controller (Programmable Logic Controller, PLC) to replace conventional control devices since the relay, PLC has been rapid development in various parts of the world have been widely used. At the same time, PLC39。 and digital input and output operation to control all types of machinery and production process. The preparation of the user control procedures to express the production process requirements and advance into the PLC user program memory. Runtime by storing the contents one by one the implementation of procedures to plete the process required to operate. PLC39。s these automatic control question, the programmable controller (PLC) has bee one of solution most effective tools. When PLC control system design should pay attention to the following several spots. one, programmable controller (PLC) and programmer39。s LG and so on, how select and purchase the PLC product? 1. The system first should determine that the system uses PLC with the PLC single plane control to form the work, from this calculates the input, the output (I/O) the points, and when selects and purchases PLC must in the actual need points foundation reserve 10% remainders. 2. The definite load type acts according to the PLC outport to have the load is the cocurrent or the exchange, is the big electric current or the undercurren