Summary post for the “One Question per Day” section in the control system technology exchange area

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Summary post of the “One Question per Day” section in the Control System Technology Discussion Area: 1. [One Question per Day 20090101] Communication methods between DCS/PLC systems: http://bbs.hcbbs.com/thread-362333-1-1.html 2. [One Question per Day 20090102] How many types are there for the patterns of change in controlled parameters? http://bbs.hcbbs.com/thread-363025-1-1.html 3. [One Question per Day 20090103] What are the similarities and differences between the HART protocol and fieldbuses? http://bbs.hcbbs.com/thread-363630-1-1.html 4. [One Question per Day 20090104] The shutdown levels of ESD systems: http://bbs.hcbbs.com/thread-364221-1-1.html 5. [One Question per Day 20090105] Network topologies of DCS systems and their advantages and disadvantages: http://bbs.hcbbs.com/thread-364857-1-1.html 6. [One Question per Day 20090106] Types of Emerson DCS cards and their functions: http://bbs.hcbbs.com/thread-366023-1-1.html 7. [One Question per Day 20090107] Let’s discuss control systems for preventing surge in compressors and for adjusting their speed: http://bbs.hcbbs.com/thread-367037-1-1.html 8. [One Question per Day 20090108] What types of faults have occurred with Yokogawa CS3000/1000 systems? How was it solved? http://bbs.hcbbs.com/thread-367908-1-1.html 9. 【Daily Question 20090109】What is included in the DCS/PLC power supply load calculation? http://bbs.hcbbs.com/thread-368983-1-1.html 10. 【Daily Question 20090110】What considerations should be taken when selecting DCS/PLC analog I/O cards? http://bbs.hcbbs.com/thread-369684-1-1.html 11. 【Daily Question 20090111】What considerations should be taken when selecting digital I/O cards for DCS/PLC systems? http://bbs.hcbbs.com/thread-370317-1-1.html 12. 【Daily Question 20090112】Types of Yokogawa DCS cards. http://bbs.hcbbs.com/thread-370702-1-1.html 13. 【Daily Question 20090113】Discussion on the differences between DCS and FCS http://bbs.hcbbs.com/thread-371748-1-1.html 14. 【Daily Question 20090114】Discussion on DCS system grounding http://bbs.hcbbs.com/thread-372419-1-1.html 15. 【Daily Question 20090115】All aspects of DCS maintenance http://bbs.hcbbs.com/thread-373187-1-1.html 16. 【Daily Question 20090116】What are the common communication faults in DCS/PLC? http://bbs.hcbbs.com/thread-374159-1-1.html 17. 【Daily Question 20090117】In-depth discussion on hot standby and redundancy http://bbs.hcbbs.com/thread-374714-1-1.html 18. 【Daily Question 20090118】Common faults of HONYWELL DCS and their solutions http://bbs.hcbbs.com/thread-375261-1-1.html 19. 【Daily Question 20090119】What are the requirements for implementing the signal that allows a pump to start in a PLC? http://bbs.hcbbs.com/thread-375909-1-1.html 20. [Daily Question 20090120] Is there any relationship between the setting of historical data acquisition time and the data refresh frequency in DCS configuration? http://bbs.hcbbs.com/thread-376267-1-1.html 21, 22. 【Daily Question 20090122】Summary of empirical values for PID control parameters in systems from various DCS/PLC manufacturers http://bbs.hcbbs.com/thread-377527-1-1.html 23. 【Daily Question 20090203】Contents of daily maintenance for DCS operating systems and issues to be noted http://bbs.hcbbs.com/viewthread.php?tid=381756&page=1&extra=page%3D1 24. 【Daily Question 20090204】Introduction to several processes in automated control http://bbs.hcbbs.com/thread-382513-1-1.html 25. 【Daily Question 20090205】What tasks should be carried out during the cold testing of an automatic control system? http://bbs.hcbbs.com/thread-383255-1-1.html 26. [Daily Question 20090206] Differential control is not used for automatic pressure and flow regulation, while differential control is often employed for temperature regulation. http://bbs.hcbbs.com/viewthread.php?tid=383895&page=1&extra=page%3D1 27. [Daily Question 20090207] Why is a orifice plate installed in front of a control valve? http://bbs.hcbbs.com/thread-384688-1-1.html 28. [Daily Question 20090208] Why does the technical specification for instruments with 4–20mA output require a load resistance of 250Ω? http://bbs.hcbbs.com/thread-385097-1-1.html 29. [Daily Question 20090209] Smart transmitters use the HART protocol; what are the reasons for the requirements regarding loop resistance and what are the consequences if these limits are exceeded? http://bbs.hcbbs.com/thread-385585-1-1.html 30. What are complex control systems? http://bbs.hcbbs.com/viewthread.php?tid=386046&page=1&extra=page%3D1 31、【Daily Question 20090211】Can the output of a current source be left open-circuited for an extended period of time? Why? What consequences will it have? http://bbs.hcbbs.com/viewthread.php?tid=386945&page=1&extra=page%3D1 32. [Daily Question 20090212] Interferences in PID control systems are unpredictable and difficult to suppress, but their destructive effects on the system can be controlled. http://bbs.hcbbs.com/viewthread.php?tid=387854&page=1&extra=page%3D1 33. [Daily Question 20090213] A few simple fill-in-the-blank questions to keep the forum active! http://bbs.hcbbs.com/thread-388726-1-1.html 35. [Daily Question 20090214] Several fill-in-the-blank questions. http://bbs.hcbbs.com/thread-389337-1-1.html 36. [Daily Question 20090215] Are there any regulations regarding the length of pressure conduits for instruments? What is the optimal length? http://bbs.hcbbs.com/thread-389961-1-1.html 37. [Daily Question 20090216] What types of modules do PS, CPU, CP, AI, etc. refer to in control system modules? http://bbs.hcbbs.com/thread-390712-1-1.html 38. [Daily Question 20090217] Does a DCS require no maintenance to operate properly during production? http://bbs.hcbbs.com/thread-391639-1-1.html 39. 【Daily Question 20090218】Why is the sensing element of a differential pressure transmitter designed as a diaphragm box structure? Would a single diaphragm work? http://bbs.hcbbs.com/thread-392504-1-1.html 40. 【Daily Question 20090219】Fill in the blanks related to instruments. http://bbs.hcbbs.com/thread-393472-1-1.html 41. 【Daily Question 20090220】Functions and technical requirements of UPS power supplies in control systems. http://bbs.hcbbs.com/thread-394239-1-1.html 42. 【Daily Question 20090222】 How to choose a gasket when installing a pressure gauge? http://bbs.hcbbs.com/thread-396992-1-1.html 43. 【Daily Question 20090223】What are the three most commonly used temperature scales, and what is the relationship between them? http://bbs.hcbbs.com/thread-396990-1-1.html 44. 【Daily Question 20090224】Compensation formula for flow meters when performing temperature and pressure compensation on the host computer http://bbs.hcbbs.com/thread-397845-1-1.html 45. 【Daily Question 20090225】Multiple-choice questions http://bbs.hcbbs.com/thread-399206-1-1.html 46. 【Daily Question 20090226】Multiple-choice questions http://bbs.hcbbs.com/thread-400283-1-1.html Summary thread of “Daily Question” in the area for exchanging ideas on automatic control system design and integration technologies 1. 【Daily Question 20090101】Design and selection of field instruments http://bbs.hcbbs.com/thread-362337-1-1.html 2. 【Daily Question 20090102】Composition and meaning of instrument symbols http://bbs.hcbbs.com/thread-363020-1-1.html 3. 【Daily Question 20090103】Contents of individual instrument debugging http://bbs.hcbbs.com/thread-363688-1-1.html 4. 【Daily Question 20090104】What does the preliminary design of instruments include? http://bbs.hcbbs.com/thread-364235-1-1.html 5. 【Daily Question 20090105】What are the common designs for instrument control circuits? http://bbs.hcbbs.com/thread-365093-1-1.html 6. [Daily Question 20090106] How are analytical instruments used in various industries? http://bbs.hcbbs.com/thread-366199-1-1.html 7. [Daily Question 20090107] Analysis of integration issues in cottages http://bbs.hcbbs.com/thread-367055-1-1.html 8. [Daily Question 20090108] What are the application characteristics of switch-type instruments in various industries? http://bbs.hcbbs.com/thread-368022-1-1.html 9. 【Daily Question 20090109】What does the design of the fire and gas system (F&G) include? http://bbs.hcbbs.com/thread-368998-1-1.html 10. 【Daily Question 20090110】What are the characteristics of integrated systems or system integration? http://bbs.hcbbs.com/thread-369691-1-1.html 11. 【Daily Question 20090111】What are the common instrument control schemes for large-scale power generation units? http://bbs.hcbbs.com/thread-370325-1-1.html 13. What are the design requirements for instrument air supply and power supply? http://bbs.hcbbs.com/thread-371829-1-1.html 14. What are the design requirements for grounding of field instruments? http://bbs.hcbbs.com/thread-372435-1-1.html 15. Application and understanding of instrument specifications http://bbs.hcbbs.com/thread-373192-1-1.html 16. What types of failures have occurred with the electro-hydraulic actuators used at Lanlian? http://bbs.hcbbs.com/thread-373990-1-1.html 17. 【Daily Question 20090117】What are the analytical instruments used in laboratories? http://bbs.hcbbs.com/thread-374721-1-1.html 18. 【Daily Question 20090118】What are the control advantages of control valves? http://bbs.hcbbs.com/thread-375263-1-1.html 19. 【Daily Question 20090119】Test your skills in fault diagnosis http://bbs.hcbbs.com/thread-375745-1-1.html 20. 【Daily Question 20090120】Can recommended manufacturers be listed in the remarks section of the instrument data sheet? http://bbs.hcbbs.com/thread-376287-1-1.html 21. 【Daily Question 20090121】What type of instrument is suitable for measuring the level in tanks used for the alkaline cleaning of gasoline or diesel? http://bbs.hcbbs.com/thread-376929-1-1.html 22. 【Daily Question 20090122】Discussion on the use of LCD displays in PLC field control panels http://bbs.hcbbs.com/thread-377500-1-5.html 23. 【Daily Question 20090123】The impact of cable trays and signal wiring on signals http://bbs.hcbbs.com/thread-377930-1-5.html 24. 【Daily Question 20090124】Lightning protection measures for instruments http://bbs.hcbbs.com/thread-378377-1-5.html 25. 【Daily Question 20090209】What are the requirements regarding the grounding of the shielding layer of shielding wires? Why? http://bbs.hcbbs.com/thread-385515-1-4.html 26. 【Daily Question 20090210】What are the main bases for preparing a professional construction organization plan? http://bbs.hcbbs.com/thread-385954-1-4.html 27. 【Daily Question 20090211】What are the key aspects of drawing review? http://bbs.hcbbs.com/thread-386755-1-3.html 28. 【Daily Question 20090212】What does technical management in anti-accident measures for thermal protection entail? http://bbs.hcbbs.com/thread-387745-1-3.html 29. 【Daily Question 20090213】 Survey on the utilization rate of the ESD emergency shutdown system http://bbs.hcbbs.com/thread-388652-1-3.html 30. 【Daily Question 20090215】 Fault analysis questions related to orifice plates http://bbs.hcbbs.com/thread-390063-1-3.html 31. 【Daily Question 20090216】 What items should be checked for thermal instruments before they are put into use? http://bbs.hcbbs.com/thread-390704-1-3.html 32. [Daily Question 20090217] Briefly describe the principles for selecting standard throttling devices. http://bbs.hcbbs.com/thread-391750-1-2.html 33. [Daily Question 20090218] What are the characteristics of cascade control systems? In what applications are they mainly used? http://bbs.hcbbs.com/thread-392487-1-2.html 34. [Daily Question 20090219] Briefly describe the steps for tuning PID parameters using the trial and error method. http://bbs.hcbbs.com/thread-393474-1-2.html 35. [Daily Question 20090220] A few instrument-related questions to test your knowledge. http://bbs.hcbbs.com/thread-394677-1-2.html 36. [Daily Question 20090221] Questions regarding the butterfly valve at the inlet of the main fan. http://bbs.hcbbs.com/thread-395632-1-1.html 37. [Daily Question 20090222] Briefly describe the functions of each component in the structure of digital thermal display instruments. http://bbs.hcbbs.com/thread-396400-1-1.html 38. Why should differential pressure flow meters generally not be used below 30% of their full scale? http://bbs.hcbbs.com/thread-396935-1-1.html 39. 【Daily Question 20090226】What are the instruments subject to mandatory inspection in your company? http://bbs.hcbbs.com/thread-399947-1-1.html 40. 【Daily Question 20090227】Please discuss the management of instrument installation. http://bbs.hcbbs.com/thread-401154-1-1.html Posts related to March activities 1. 【Daily Question 20090301】The roles of instrument technicians during the commissioning of new installations. http://bbs.hcbbs.com/thread-402929-1-1.html 2. 【Daily Question 20090302】Which installations should be provided with protective grounding? http://bbs.hcbbs.com/thread-403400-1-2.html 3. 【Daily Question 20090303】Which devices should be grounded for operational purposes? http://bbs.hcbbs.com/thread-404481-1-1.html 4. [Daily Question 20090304] Does anyone know how the characteristic curve of a centrifugal compressor is determined? http://bbs.hcbbs.com/thread-405643-1-1.html 5. [Daily Question 20090305] What does instrument calibration involve? http://bbs.hcbbs.com/thread-406683-1-1.html 6. 【Daily Question 20090306】Several questions related to instrument errors http://bbs.hcbbs.com/thread-407714-1-1.html 7. 【Daily Question 20090307】Several multiple-choice questions on range modulation http://bbs.hcbbs.com/thread-408665-1-1.html 8. 【Daily Question 20090308】Are the thermoelectric properties of compensation wires exactly the same as those of the thermocouples they are matched with? http://bbs.hcbbs.com/thread-409487-1-1.html 9. 【Daily Questions 20090312~15】Instrumentation devices and production safety http://bbs.hcbbs.com/viewthread.php?tid=412971&page=1#pid2206288 10. 【Daily Question 20090316】Emergency plans for the instrumentation field http://bbs.hcbbs.com/viewthread.php?tid=416811&page=1#pid2227332 11. 【Daily Question 20090317】What safety measures should be considered in control systems? http://bbs.hcbbs.com/thread-417866-1-1.html 12. 【Daily Question 20090318】Discuss how to improve the control quality of control systems from the perspective of measuring and transmitting instruments http://bbs.hcbbs.com/thread-418850-1-1.html 13. 【Daily Question 20090319】How can the control quality of a control system be improved from the perspective of control instruments? http://bbs.hcbbs.com/thread-419805-1-1.html 14. 【Daily Question 20090320~21】What are the key points for selecting a DCS? http://bbs.hcbbs.com/thread-420791-1-1.html 15. [Daily Question 20090322] Please explain what types of measuring instruments and control methods are available for centrifugal compressors. http://bbs.hcbbs.com/thread-422166-1-1.html 16. [Daily Question 20090323] In what ways can the reliability and safety of distributed control systems be improved? http://bbs.hcbbs.com/thread-422995-1-1.html 17. 【Daily Question 20090324】What are the common programming or configuration languages used in distribution systems? http://bbs.hcbbs.com/thread-424252-1-1.html 18. 【Daily Question 20090325】Methods for measuring the liquid level in high-pressure containers http://bbs.hcbbs.com/thread-425186-1-1.html 19. 【Daily Question 20090326】What are the causes of short circuits? What are the hazards? Can short circuits be utilized in production? http://bbs.hcbbs.com/thread-426017-1-1.html 20. 【Daily Question 20090327】What are the basic schemes for combustion control systems? http://bbs.hcbbs.com/thread-427083-1-1.html 21. [Daily Question 20090328] Popularizing knowledge about instruments (already summarized) http://bbs.hcbbs.com/thread-428094-1-1.html 22. [Daily Question 20090329] Popularizing knowledge about instruments http://bbs.hcbbs.com/thread-428794-1-1.html 23. [Daily Question 20090330] Popularizing knowledge about instruments http://bbs.hcbbs.com/thread-429516-1-1.html 24. [Daily Question 20090331] Popularizing knowledge about instruments http://bbs.hcbbs.com/thread-430472-1-1.html Posts related to the daily question activity in April: 1. [Daily Question 20090401] Management of PLC systems in factories http://bbs.hcbbs.com/thread-431433-1-38.html 2. [Daily Question 20090402] Knowledge about instruments http://bbs.hcbbs.com/thread-432616-1-1.html 3. [Daily Question 20090403] Analytical instruments used in environmental monitoring http://bbs.hcbbs.com/thread-433677-1-1.html 4. [Daily Question 20090404] Types of control valves http://bbs.hcbbs.com/thread-434647-1-1.html 5. [Daily Question 20090405] Choosing between air-operated control valves that operate on air opening or air closing principle http://bbs.hcbbs.com/thread-435159-1-1.html 6. [Daily Question 20090406] Knowledge about air-operated control valves http://bbs.hcbbs.com/thread-435801-1-1.html 7. [Daily Question 20090407] How to choose between air-opening and air-closing types of air-operated control valves? http://bbs.hcbbs.com/thread-436734-1-1.html 8. [Daily Question 200090408] Cases of troubleshooting electromagnetic flowmeters in the field http://bbs.hcbbs.com/thread-437320-1-1.html 9. [Daily Questions 200090409~10] What types of faults occur with orifice plate flowmeters during use in the field, and how are they resolved? http://bbs.hcbbs.com/thread-438266-1-1.html 10. 【Weekend Question 20090411~12】Discuss the structure of a company’s instrument workshop. http://bbs.hcbbs.com/thread-439759-1-1.html 11. 【Daily Question 200090413】What types of failures have occurred with differential pressure transmitters in field use, and how were they resolved? http://bbs.hcbbs.com/thread-439757-1-1.html 12. 【Daily Question 20090414】What types of failures have occurred with turbine flowmeters during use in the field, and how were they resolved? http://bbs.hcbbs.com/thread-442803-1-1.html ######################################################################################## Please, moderators, update the summary of the daily questions in your replies. This post was last edited by Mobei Yihai on 2009-4-17 at 21:35.]