Comments for ISA Interchange http://automation.isa.org Automation news and technical content from ISA Sat, 05 May 2012 12:10:00 +0000 hourly 1 http://wordpress.org/?v=3.3.2 Comment on How do I check out DCS I/O at the panel shop? by Nsubbu135 http://automation.isa.org/2012/05/how-do-i-check-out-dcs-io-at-the-panel-shop/#comment-100 Nsubbu135 Sat, 05 May 2012 12:10:00 +0000 http://automation.isa.org/?p=3418#comment-100 Assuming no loop elements effects are required use 4 to 20 mA DC aand check at 3 points min the output shall be 4 to 20 mA for direct supply or 20 to 4 mA aas the case may be In case of split ranges for dual control valve 4to 12 and 12 to 20 out put may be fed to split valve positioners On in put loads may be introduced and increased so that 4 to 20 mA is not reduced for a total loop resistance of 600 Ohms input voltage is 25 V DC Or Assuming no loop elements effects are required use 4 to 20 mA DC aand check at 3 points min
the output shall be 4 to 20 mA for direct supply or 20 to 4 mA aas the case may be
In case of split ranges for dual control valve 4to 12 and 12 to 20 out put may be fed to split valve positioners
On in put loads may be introduced and increased so that 4 to 20 mA is not reduced for a total loop resistance of 600 Ohms input voltage is 25 V DC
Or

]]> Comment on How do you know when feed-forward is needed? by How to Succeed – Part 7 » Modeling and Control http://automation.isa.org/2011/12/how-do-you-know-when-feed-forward-is-needed/#comment-99 How to Succeed – Part 7 » Modeling and Control Sat, 05 May 2012 06:22:43 +0000 http://automation.isa.org/?p=2617#comment-99 [...] The key to achieving these objectives is to choose the best pairing of manipulated and controlled variables per relative gain analysis, using cascade control to isolate nonlinearities (valve and process) and disturbances by a fast secondary loop, and using feedforward control for coordinating loops and rejecting load disturbances. Secondary flow loops can compensate for pressure upsets and installed valve characteristic nonlinearities. Secondary cooling and heating temperature loops can make the vessel temperature loop nearly linear. Secondary flow loops and plant wide flow feedforward control can enable a plant to reach and maintain optimum operating points as discussed in the InTech article ”Feedforward control enables flexible, sustainable manufacturing.“ Some key considerations are discussed in the answer to an ISA Mentor program question posted on ISA Interchange website How do you know when feed-forward control is needed? [...] [...] The key to achieving these objectives is to choose the best pairing of manipulated and controlled variables per relative gain analysis, using cascade control to isolate nonlinearities (valve and process) and disturbances by a fast secondary loop, and using feedforward control for coordinating loops and rejecting load disturbances. Secondary flow loops can compensate for pressure upsets and installed valve characteristic nonlinearities. Secondary cooling and heating temperature loops can make the vessel temperature loop nearly linear. Secondary flow loops and plant wide flow feedforward control can enable a plant to reach and maintain optimum operating points as discussed in the InTech article ”Feedforward control enables flexible, sustainable manufacturing.“ Some key considerations are discussed in the answer to an ISA Mentor program question posted on ISA Interchange website How do you know when feed-forward control is needed? [...]

]]> Comment on Part II – What are the important criteria for selecting a system integrator? by Juliann Grant http://automation.isa.org/2012/04/part-ii-what-are-the-important-criteria-for-selecting-a-system-integrator/#comment-96 Juliann Grant Thu, 19 Apr 2012 20:49:02 +0000 http://automation.isa.org/?p=3209#comment-96 Thanks! Thanks!

]]> Comment on Part II – What are the important criteria for selecting a system integrator? by Plant Automation http://automation.isa.org/2012/04/part-ii-what-are-the-important-criteria-for-selecting-a-system-integrator/#comment-95 Plant Automation Thu, 19 Apr 2012 08:58:00 +0000 http://automation.isa.org/?p=3209#comment-95 good blog good blog

]]> Comment on Insights Behind ISA’s Building Automation Systems Division by Pradeep Sweetball http://automation.isa.org/2012/04/insights-behind-isas-building-automation-systems-division/#comment-94 Pradeep Sweetball Fri, 13 Apr 2012 07:59:00 +0000 http://automation.isa.org/?p=3237#comment-94 Thank You The given information is very effective i will keep updated with the same <a href="http://www.sweetball.in" rel="nofollow">industrial automation </a> Thank You

The given information is very effective
i will keep updated with the same

industrial automation

]]> Comment on Part I – What are the important criteria for selecting a system integrator? by Part II – What are the important criteria for selecting a system integrator? | ISA Interchange http://automation.isa.org/2012/03/part-i-what-are-the-important-criteria-for-selecting-a-system-integrator/#comment-91 Part II – What are the important criteria for selecting a system integrator? | ISA Interchange Fri, 06 Apr 2012 14:15:48 +0000 http://automation.isa.org/?p=3186#comment-91 [...] For more information, see Part I for the first answer to this important question. No related [...] [...] For more information, see Part I for the first answer to this important question. No related [...]

]]> Comment on ISA Collaborates with San Jacinto College by Pradeep Nagar http://automation.isa.org/2012/03/isa-collaborates-with-san-jacinto-college/#comment-90 Pradeep Nagar Fri, 06 Apr 2012 09:14:00 +0000 http://automation.isa.org/?p=3126#comment-90 Thank You The given information is very effective i will keep updated with the same <a href="http://www.sweetball.in" rel="nofollow">industrial automation training</a> Thank You

The given information is very effective
i will keep updated with the same

industrial automation training

]]> Comment on Insights Behind ISA’s Building Automation Systems Division by Ekovac http://automation.isa.org/2012/04/insights-behind-isas-building-automation-systems-division/#comment-89 Ekovac Thu, 05 Apr 2012 15:24:00 +0000 http://automation.isa.org/?p=3237#comment-89 ISA Insights also interviewed Jacob Jackson in December 2011 regarding the new Building Automation Systems Division. You can read it here: http://www.isa.org/Content/ContentGroups/News/ISA_Insights1/201113/December43/ISA_division_introductions_QandA__Building_Automation_Systems_Division.htm?utm_source=Eloquaekovac%40isa.org&utm_medium=email&utm_campaign=ISA_Insights_Dec2011_EBK ISA Insights also interviewed Jacob Jackson in December 2011 regarding the new Building Automation Systems Division. You can read it here:
http://www.isa.org/Content/ContentGroups/News/ISA_Insights1/201113/December43/ISA_division_introductions_QandA__Building_Automation_Systems_Division.htm?utm_source=Eloquaekovac%40isa.org&utm_medium=email&utm_campaign=ISA_Insights_Dec2011_EBK

]]> Comment on Annubar or orifice meter? by julianngrant http://automation.isa.org/2012/03/annubar-or-orifice-meter/#comment-88 julianngrant Sun, 01 Apr 2012 01:39:00 +0000 http://automation.isa.org/?p=3155#comment-88 My answer in the post is supportive of annubars whereas Ram's is not. I don't think either one of us says you should not use annubars in large line sizes. I agree target meters are no longer used and the ultraonic meters I know of did not work well but that was in the 1990s. The technology has probably improved in the last decade. - posted on behalf of Greg McMillan My answer in the post is supportive of annubars whereas Ram’s is not. I don’t think either one of us says you should not use annubars in large line sizes. I agree target meters are no longer used and the ultraonic meters I know of did not work well but that was in the 1990s. The technology has probably improved in the last decade. – posted on behalf of Greg McMillan

]]> Comment on Annubar or orifice meter? by Shafi A Syed http://automation.isa.org/2012/03/annubar-or-orifice-meter/#comment-86 Shafi A Syed Thu, 29 Mar 2012 13:36:00 +0000 http://automation.isa.org/?p=3155#comment-86 I beg to differ on the above suggestion. Averaging Pitot Tubes are well suited for large line sizes with moderate accuracy and in service where there are no particles. The other flow measurement technologies listed above have issues like in accuracy like in case of doppler flow meter ( which also requires certain amount of solid particles to reflect the waves ) which in this case ( being oil to storage ) is very remote. Strap on or Clamp on Ultrasonic have issues with the strapping when the pipe thermally expands and target flowmeters are rarely used in process industry. Please contact your local Emerson reperesentative to get more information and application specific information on Averaging pitot tube ( Annubar in case of Rosemount-Emerson) I beg to differ on the above suggestion. Averaging Pitot Tubes are well suited for large line sizes with moderate accuracy and in service where there are no particles. The other flow measurement technologies listed above have issues like in accuracy like in case of doppler flow meter ( which also requires certain amount of solid particles to reflect the waves ) which in this case ( being oil to storage ) is very remote. Strap on or Clamp on Ultrasonic have issues with the strapping when the pipe thermally expands and target flowmeters are rarely used in process industry.

Please contact your local Emerson reperesentative to get more information and application specific information on Averaging pitot tube ( Annubar in case of Rosemount-Emerson)

]]>