第五章单元测试
- For PLC of FX3U series, the DECO instruction is______________Instructions.（ ）
- All kinds of PLC programming software have on-line monitoring function, but the forms and functions are different. Online monitoring can be carried out in "STOP" or "RUN" mode, but only I / O point status monitoring can be carried out in "STOP" mode, not the operation of the program.（ ）
- The online monitoring function is based on the premise of ensuring the normal communication between the programming software and PLC. Therefore, a new project should be created first, and then the communication test between the programming software and PLC should be carried out. Only when the test is successful can I / o point status monitoring be implemented.（ ）
- The checking and mapping of electrical control circuit wiring is an important part of electrical installation and maintenance engineering. In practical engineering, it is a very practical method to check or map the I/O wiring of PLC with the help of the state monitoring function of PLC. Among them, the forced output function of soft component test is particularly suitable for the test of single point load, such as the output load of PLC is solenoid valve coil, relay contactor coil, indicator light, etc. For the test and verification of the input point, the proximity switch can also be activated or reset manually. The input point assignment of the proximity switch can be determined according to the status of PLC input point indicator light on or off. However, this observation method is easy to make mistakes, and it is better to use programming software.（ ）
- The writing or forced output of soft component status may lead to the change of PLC control. Safety must be confirmed before implementation. Taking this training activity as an example, it is required to clear the workpiece in the feeding unit silo before the test, otherwise, when the lower pushing cylinder is forced to extend, the piston rod will be stuck by the workpiece after it is extended.（ ）
A:Positioning B:Comparison C:Decoding D:Transmission
答案:Decoding
A:对 B:错
A:对 B:错
A:错 B:对
A:对 B:错
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