So-called empirical method, programming is the use of one‘s own or others ‘ experience. This method requires the user to be familiar with basic circuit conditions, grasp the basic principles of the design of ladder diagram and the programming skills, so that programs adapted for the requirements of their program experience.
1) ladder diagram of each logical line is from left the bus started to output coil ends, that is to say, in the output coil and bus can’t take any relay contacts on the right side, so the right bus often omitted
2) all input/output relays, auxiliary relays, TIM/CNT, contact number is infinite, and normally open, normally closed form can be. Therefore, when drawing ladder diagrams, structure should be as simple as possible (so that there is a clear relationship between series and parallel), instead of using complex structures to reduce the number of contacts.
3) all output relays can be used as an internal auxiliary relays, and contact number is infinite; but do not enter relay as an internal auxiliary relays.
4) output coil cannot be directly connected to the bus left, if there is such a need, through an internal do not use auxiliary relay normally closed contact or 25513lai connection ON relay.
5) with a coil cannot be reused, the illegal circuit, in the program found a mistake, DOUBLE COIL error message will appear.
6) two or more coils can be connected in parallel not in series.
7) run is to first address to the END of the program instructions, from left to right and from top to bottom in the order. To consider when programming sequence of procedures. As shown in Figure 7-7, when debugging a program, program can be divided into several segments, each insert an END instruction, debugger paragraph by paragraph so that they can, after the first set, by deleting the first END inserted instructions, so that you can debug paragraph by paragraph; until until the program set as a whole.
PLC ONE 