Hi, I have 7 years of experience as a maintenance / PLC programmer in a fairly old steel mill. I was the one who converted PLC2 to CtrlLGx platform ten years ago.
After that, I went to Oil and Gas engineering firm where I was able to learn common practices in programming of O&G processing plants, compressors and other.
Since logic in the steel mill was just converted from PLC2 and PLC5 to CtrlLgx there is none of signal conditioning that I see O&G sector uses (Plant PAx system etc...).
I also remember almost all of the digital switches (proxy, limit etc...) are programmed as NO switches.
Another difference is a control voltage for field devices - it's all 120V in manufacturing vs 24V in O&G.
I started to think how much of a benefit would it be to program machinery with normally closed switches or at least as NO with the end of the line resistor for open circuit detection.
Also the signal conditioning used in oil and gas programming practice - do you think it would help in a purely sequencing /digital IO facility vs. process environment with it's 90% analog devices.
So for a professional manufacturing PLC Automation engineers who also have background in O&G or (as my American friend call it) Petroleum industry, what's the current trend in the programming in manufacturing ?
After that, I went to Oil and Gas engineering firm where I was able to learn common practices in programming of O&G processing plants, compressors and other.
Since logic in the steel mill was just converted from PLC2 and PLC5 to CtrlLgx there is none of signal conditioning that I see O&G sector uses (Plant PAx system etc...).
I also remember almost all of the digital switches (proxy, limit etc...) are programmed as NO switches.
Another difference is a control voltage for field devices - it's all 120V in manufacturing vs 24V in O&G.
I started to think how much of a benefit would it be to program machinery with normally closed switches or at least as NO with the end of the line resistor for open circuit detection.
Also the signal conditioning used in oil and gas programming practice - do you think it would help in a purely sequencing /digital IO facility vs. process environment with it's 90% analog devices.
So for a professional manufacturing PLC Automation engineers who also have background in O&G or (as my American friend call it) Petroleum industry, what's the current trend in the programming in manufacturing ?
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