5SHY4045L0001 3BHB018162R0001 I/O Terminal Subsystem

5SHY4045L0001 3BHB018162R0001 I/O Terminal Subsystem

5SHY4045L0001 3BHB018162R0001 The use of the same relay coil twice in the same program is called a dual coil output. Dual coil outputs are prone to malfunction and should be avoided as much as possible in the program. If a dual coil output is necessary, it can be set and reset (e.g. SQ4.0 or RQ4.0 for S7-300). For non-critical devices, you can save resources by connecting multiple contacts in series on the hardware before connecting to the PLC inputs, or by programming the PLC to reduce the number of I/O points.

5SHY4045L0001 3BHB018162R0001 Make PLC multiple outputs for fixed value 1 (normally closed), can be accomplished by using a word transfer instruction, for example, Q2.0, Q2.3, Q2.5, Q2.7 are all 1 at the same time, you can use an instruction to transfer hexadecimal data 0A9H directly to QW2 can be. For example, if we use a button to control the start/stop of a device, we can use bifurcation to realize it.

5SHY4045L0001 3BHB018162R0001 application of modular programming ideas: we can be positive and negative self-locking interlock turn program encapsulated into a module, positive and negative rotation point of time encapsulated into a module, in the PLC program we can repeatedly call the module, not only to reduce the amount of programming, but also to reduce the amount of memory occupied, is conducive to large-scale PLC program preparation. PLC control system program debugging generally includes I / O terminal testing and system debugging two parts, a good debugging steps to accelerate the process of assembly debugging.