rockets1989
Member
I am a beginner at RSLogix 5000 and in ladder logic in general. I am tasked with making sense of an existing program and reprogramming it to make it more efficient. I have a few questions.
1. I have a BOOL Tags named "PSC1107A_BLOCKED" and "SIDE_A_BLOCKED" that have a value of 0. In one of the rungs on the program it looks like this
When a value of 1 is written into the tag "PSC1107A_BLOCKED" from an OTE somewhere else in the program, will the XIC get toggled (turn green) and the XIO untoggle? If so, won't both the OTL and OTU "SIDE_A_BLOCKED" become energized? Is this bad programming or is there a fundamental of ladder logic that I am not aware of?
I asked someone that I work with to explain it to me and he said that these parallel branches are a way to make the OTU "SIDE_A_BLOCKED" stay true until the XIC "PSC1107A_BLOCKED" goes true and the OTL "SIDE_A_BLOCKED" goes true. In this explanation, the toggling of the XIO acts as a jumper until the "PSC1107A_BLOCKED" writes a value of 0. But this doesn't make sense to me since there will be two values for a single tag.
2. (Question not associated with the image) A rung has an OTE that is toggled because the tag has a value of 1. When this rung goes true, does the tag associated with the OTE receive a value of 0?
3. Same question as Questoin 2 except asking about a toggled OTL instead of toggled OTE. What happens to the value of the tag after the rung goes true?
Thanks
1. I have a BOOL Tags named "PSC1107A_BLOCKED" and "SIDE_A_BLOCKED" that have a value of 0. In one of the rungs on the program it looks like this
When a value of 1 is written into the tag "PSC1107A_BLOCKED" from an OTE somewhere else in the program, will the XIC get toggled (turn green) and the XIO untoggle? If so, won't both the OTL and OTU "SIDE_A_BLOCKED" become energized? Is this bad programming or is there a fundamental of ladder logic that I am not aware of?
I asked someone that I work with to explain it to me and he said that these parallel branches are a way to make the OTU "SIDE_A_BLOCKED" stay true until the XIC "PSC1107A_BLOCKED" goes true and the OTL "SIDE_A_BLOCKED" goes true. In this explanation, the toggling of the XIO acts as a jumper until the "PSC1107A_BLOCKED" writes a value of 0. But this doesn't make sense to me since there will be two values for a single tag.
2. (Question not associated with the image) A rung has an OTE that is toggled because the tag has a value of 1. When this rung goes true, does the tag associated with the OTE receive a value of 0?
3. Same question as Questoin 2 except asking about a toggled OTL instead of toggled OTE. What happens to the value of the tag after the rung goes true?
Thanks
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