Interlocking Logic Diagramming*
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Everyone, take a look at this image – is there any problem with it? Experts, please help explain it. Thank you
I couldn’t understand the first word – two limit switches? A limit switch? Why use one’s own limit switch to control its own switch? Is it death in that immobility, or an infinite loop?
There should be two switches, one for turning on and one for turning off
Logically, there doesn’t seem to be any major issues from a visual inspection, right?
This post was last edited by ZhiGE on 2021-8-28 07:55. Logical description: 1. The electric valve at the inlet of the second stage of the propylene refrigeration compressor is closed (the closing limit switch XZSC16361 is set to 1, while the opening limit switch XZSO16361 is set to 0); the valve closure indicator (XZLC16361) shows that the valve is fully closed. 2. The electric valve at the second-stage inlet of the propylene refrigeration compressor is open (the shutdown limit switch XZSC16361 is set to 0, while the opening limit switch XZSO16361 is set to 1); the valve opening indicator (XZLO16361) shows that it is fully open ； And send the valve fully open signal (XZSO-16361) to logic S1601-5. PRC: Propylene Refrigerant Compressor MOV: Motor Operated Valve
1. The following description is incorrect; it should be “enabled”. 2. There are errors or false signals regarding the valve position; it is not recommended to use two valve positions in a back-and-forth manner to determine whether the valve is fully open. It is recommended to use: a valve-opening command + XZSO to determine whether the valve has opened fully.
I need to understand this subject better; could someone recommend some teaching videos or materials on this topic? Thank you
Bro, I think you’re right, but I have the feeling that his logic diagram is executed from right to left
xzsc is the valve closure signal, while xzso is the valve opening signal