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EM231 measurement 亮美is unstable

Problem: EM231 mea答報surement is unstabl街呢e

      

solution:

 If the environm視廠ent clean ground on t是文he ground, if the environment 白件is poor ground 老商do not ground, do not know the 鐘討environment of 體男the ground conditions, can ch慢生oose not to grou靜多nd.


How to make RS232 cab店什le

Question: How to ma那懂ke a self-made RS232 cable

solution:

I have no company 雪業programming cable, and the use好城 of our products for 坐南RS232 communication, you can吃相 make their own RS232 cabl的技e.

Desktop comes with nine 吧物pin 232 serial port, an笑鄉d notebook computers can use USB銀友 to RS232 to get 山舞232 serial port. Our 內秒CPU on the RS232 communication pi海坐n definition and computer lead-out RS醫到232 definition is not the same, 和匠need to be converted.師裡 The specific con到車version is: 2 (PC) -9 (CPU), 3 (PC吧會) -2 (CPU), 5 (PC) -5 (CPU).


Common problems with temperature me明開asurement modules

Q: Does the EM231 TC need 村女to compensate f木金or the wire?

A: EM231 TC can和作 be set to cold-校拍end compensation, but stil北綠l need to compensate 技我the wire for thermocouple fre知兒e end compensation.


Q: Why does the EM light of th習雪e EM231 RTD and EM231 T日綠C always blink?

A: If disconnection detection i作用s selected, it may be brok慢吧en. EM231 RTD unused channel co低新nnected to 100 oh用微m resistance, and for the EM23麗紙1 TC will need to short the unus男她ed channel.


Q: What is positiv司也e calibration, negati著微ve calibration?

A: The positive calibr兒哥ation value is 3276.7 d睡一egrees (Fahrenheit or Cels紙時ius), the negat雜作ive calibration value is -3276.8 degre吧電es. If a break is detect木厭ed and the input is out of個相 range, the valu冷妹e of the corresponding channel 資山is automatically set to 少木the above calibration value.


Q: The temperatu新得re is normal when the boot, but 動雜after running for some time, found t購北hat the measured temperature is hi冷小gher than the a看腦ctual temperature. How i資通s this going?

A: Check if the thermocouple mo友老dule is installed where th票線e ambient temperature玩件 is not uniform. Such 和站as contactors and other heating東聽 devices above.多紙 When the contactor is子體 hot and the hot air rises, the少腦 temperature of the thermocouple module看電 is not uniform, and the cold但笑 junction temperature compensat生影ion of the EM231 thermocou東靜ple module is compensated 黃朋by the local temperature. T來飛his will cause the 內物cold junction temperature compens錯書ation of the EM231 thermocouple m來姐odule to be incorrect,好為 Inaccurate measurements.


Q: What is the reason why the thermocou很用ple module measures the dif放書ference between the temperature時內 and the local thermometer?

A: check in the followin廠下g order:

Check that the thermocouple is 路議consistent with the installati歌熱on location of the field t南大hermometer.

Check if there is a s畫妹hort circuit in the thermocouple sen她媽sor wiring.

Check if the thermocouple is b懂服roken.

If the above situation is normal, the市現 thermocouple module of the ch也窗annel shorted to see if th話短e temperature is too different with 關會the room temperature; a月著 large difference between th湖草e need to see whether there is a hea雪拿ting element around the module, the店線 module cooling e放對nvironment is go船體od.


How to set PID pa去銀rameters

In engineering prac答北tice, the most widely used regu男鐘lator control law for the proporti章上on, integral, differential 作新control, referred to as PID contr我子ol, also known as PID regulati件作on. PID controller has been ne身員arly 70 years of history, i做秒t is its simple structu遠商re, good stability, reliable, easy媽用 to adjust and become one of th通下e main technical contro東可l of industrial technology. When 司事the structure and 花海parameters of the controll畫有ed object can not be fully gra雜費sped or the precise mathematical mode間月l is not obtained工喝, when the other techniques of會答 the control theory are di司如fficult to adopt, the structur作妹e and parameters of t對很he system controller must be determined森上 by experience and field 的是debugging. PID control technolo木件gy is the most convenie子跳nt. That is, when we do n機坐ot fully understand a system 懂電and the control冷木led object, or can not be 湖雪effectively measured by means to聽做 obtain system parameters, the most su那話itable for PID contr小低ol technology. PID contr家技ol, in fact there are PI 民高and PD control. PID controller is器土 based on the sy體家stem error, the use of proport著劇ional, integral, differe照厭ntial control to control the am我問ount of control.

Proportional (P) control

Proportional control is one of t習話he simplest controls. The out是黃put of the cont草影roller is proportional to the input去鐘 error signal. 睡厭When there is only prop章跳ortional control, 西森there is a steady state e南月rror (Steady-state e什輛rror).

    Integral (I) c麗廠ontrol

In the integral co校做ntrol, the output o分小f the controller is prop黑玩ortional to the in信懂tegral of the input子科 error signal. F大分or an automatic control syste廠有m, if there is steady-state error after月文 entering steady-state, then the 科師control system is said to have steady-s也離tate error or referred to林電 as poor system (System with Stead低飛y-state Error). In orde廠嗎r to eliminate the steady-state erro但熱r, in the controller must be introduced通我 "integral items" an道相d "rdquo ;. The integral ter南妹m for the error depends on the ti北愛me integral, and as time in煙友creases, the integral term increa年笑ses. In this way, even if the error熱樂 is small, the integral term inc化看reases with time, which increases the o森也utput of the controller to further 好廠reduce the steady-sta湖知te error until it is equal to ze制風ro. Therefore, 友紅the proportional + 下匠integral (PI) co件冷ntroller can make the system without通湖 steady state error after enteri離那ng steady state.

   Di男兒fferential (D) contro麗開l

In differential control, th這廠e output of the controller is pro裡內portional to the diff場多erential of the i她河nput error signal (ie, 你間the rate of change 船舊in error). Autom志音atic control syst請雨em in the process o農從f overcoming the error may occur亮東 in the oscillation or even instab舞少ility. The reason for this物又 is that there is a l窗腦arge inertia compon水村ent (link) or a delay comp來森onent, which has the effect of suppr業地essing the error, and th體刀e change is always behind the 們了change of the error. The so什就lution is to make the suppression of亮用 the role of error changes &理上quot;ahead of" and that error is c視長lose to zero, the role 得物of suppression error should b船坐e zero. That is to東花 say, in the control見房ler only the introduction of the水司 proportion of 水玩the item is often not enough, the propo一紅rtion of the role of the amplifica場東tion is only the magnitude人時 of the error, and the c舊還urrent need to increase the 呢問"differential"那文; and it can predict the error 歌師So that the controller with proportio內街nal + derivative can make the contro算話l effect of the suppression error e訊務qual to zero or even negative, so 們我as to avoid the s坐現erious overshoot of the林吃 controlled quantity. So又們 for a larger inertia or lagged哥習 controlled object, the proportional +間些 differential (PD) controller市對 can improve the上嗎 dynamic characteristics of the syste章匠m during the adj窗舊ustment process.

    In the PID parame問音ters to set the time if you c銀秒an have a theoretical way內中 to determine the PID parameters of cou城說rse is the most ideal 機都method, but in practi技器cal applications, more is through the舊秒 Minato method to de服如termine the PID parameters.

    Incr畫現easing the scale factor P will general林土ly accelerate the response of 體現the system, in the case of微們 static difference i又朋s conducive to reduci花慢ng the static difference刀和, but the excessi動著ve proportion of the system will ha白劇ve a relatively做靜 large overshoot, and pro女紅duce oscillation, the stability of 爸分change Bad.

    Increasing the腦花 integration time I is子長 advantageous in redu冷很cing the overshoot, reduci樹你ng the oscillation, incr服話easing the stability of t木愛he system, but 懂訊the system static裡近 elimination time becomes long體裡er.

    Increasing the deriva高山tive time D is he靜照lpful to speed up t著金he response speed of the syst花制em, reduce the system overshoo內員t and increase the stability體路, but the system can reduce th讀化e ability to su下多ppress the disturbance.

    In the test, you can ref制去er to the above parameters on the imp章會act of the system control process男現 trends, the implementation of the吃照 first adjustment of兒司 the proportion of the paramet姐個ers, after the integral, and then the聽爸 differential adjustm機子ent steps.

    First set照家 the proportion of part. The prop算歌ortional parameter is changed麗要 from small to large and the cor資國responding system 離道response is observed until the response綠商 is fast and the overshoot is sm煙年all. If the syst紅她em has no static or 照舞static difference has 綠北been small to the allowable rang視山e, and the response curve has been s湖舊atisfied, you on國大ly need to adjust the regulator.

    If the sy拿站stem on the basis 跳懂of the adjustment of the st相資atic difference can no票店t meet the design requirements, you mus電了t join the integral l樹生ink. In the setting of the 我綠integration time will子行 be set to a relatively large value, an間師d then has adjusted t懂文he proportion of the coefficient is sl歌腦ightly reduced, and then reduce 高不the integration樂自 time, making the system林制 to maintain good dyna問慢mic performance, the static differe時美nce is eliminated. In朋討 this process, according to the問匠 system's response cu遠呢rve is good or bad to change the scal也看e factor and integration ti西是me, in order to get a satisfactory事姐 control process and tun玩章ing parameters.

    If the 好市process of adjustm火民ent in the process of repeated adjustme關靜nt of the system c他對an not get sati日草sfactory results, you慢房 can join the differen畫腦tial link. First,朋商 the differential time D is set to 0,睡機 on the basis of the gradua刀的l increase in the differen雨年tial time, while the correspond信路ing change in the propo影兵rtion of the coefficient and the integ又化ration time, step by 爸算step test, until a satisfactory西城 adjustment effect.

legend:

    &nb輛爸sp;      一學  

圖A.gif

Figure A: There is no overshoot of the 問生response curve, the proportional co呢電efficient P should be increased s會線o that the response has 是物a certain overshoot

          &nb去東sp;  

圖B.gif

Figure B: The overshoot of the購讀 response curve is too lar雜西ge and the scale 好黃factor P should be reduced to reduc光但e the overshoot o又們f the response.問事

 

圖C.gif

Figure C: The response curve 有開has a certain overshoot, but because拿體 the integration 聽地time is too long to cause the re日厭sponse can not be smooth, should黃舊 reduce the integration time

      &nb水讀sp;      

圖D.gif

圖D:響應曲線超調量偏大,積分土站時(shí)間偏小導緻響應振蕩,應該适當減小比例系數和适當增大積分時照愛(shí)間。

    &nb外多sp;     &n煙了bsp;  

圖E.gif

Figure E: Ideal respo我白nse curve.

 

Field wiring FAQ

 

一、熱電偶的走線問題
熱電偶走線問題.png
二、直流電源的共地問題

直流電源共地問題.png

三、CPU與擴展模塊接地端的接地體姐問題

擴展模塊接地端接地問題.png

四、系統接地問題

系統接地問題.png

五、觸摸屏應可靠接地

觸摸屏接地.png

六、開(kāi)關電源應可靠接地

開(kāi)關電源接地.png

七、注意防止變頻器的幹擾

防止變頻器幹擾.png

備注: 如果所有的線(動力線及信号線)都(dōu)用日能金屬蛇皮來套,那效果會(huì)很好(hǎo)。

八、直流電源應注意共地

直流電源注意共地.png

九、接線規範問題

接線規範.png

Wiring irregularity results in insta個木bility of the analog measur爸作ements

phenomenon:

EM231 4AI × 12BIT or 理也EM235 module measurement 商購is not stable

the reason:

The module input negative termin刀雜al is not connec鐘呢ted to the M terminal, ca吃樂using the module to fail to ef窗技fectively suppress the commo好用n mode voltage

Solution:

Connect the negative醫業 input of the module to the M termin件愛al.


The measured values麗知 for all channels村光 of the thermocou裡話ple module are 217

phenomenon:

The measured value of all cha還為nnels of the EM生生231 TC / PID module is 32767

the reason:

32767 indicates that th雜生e input has been disconnected, the use拿女r may have used a non-iso拿新lated thermocouple, resulting i她一n the input of 但也the module due to accidentally string年錢 higher than 30V above 自房the voltage and burned.

Solution:

Using isolated thermocouple, or take ot動資her means to ensure that the草家 input will not stri國關ng into more than 30V海近 high voltage.


124XP host, using the Siemens prog舊路ramming cable to download the 南玩program block prompt "non fatal error船如".

A: 124XP host, using the Siemens見可 programming cable to do媽城wnload the progr林月am block prompt "non fatal er很山ror".


Q: The 100 series PLC does錯內 not support the Siemens programmin北的g cable. Also note that the 店微number 100 series PLC跳友 timer counter can not exceed 127.



CTS7 231-7NF32, the last channel is n黃美ot connected to PT100, the S街請F light on the module flashes跳司.

A: CTS7 231-7NF32, the 司匠last channel is not connected to PT紅湖100, the SF flash on the module都音.


Q: The SF lamp flashes to ind站化icate that the 拍窗module has a cha弟會nnel disconnected. A 100 o熱說hm resistor can be us花這ed to access the unused子妹 channel and elimi討房nate the power alarm (SF lamp off)煙志.


COTRUST PLC power to keep d算照ata and time are?

First, the data po老人wer to maintain the化微 length of time:

CTSC-100:

1, the use of built-in butt友很on batteries, about 1 ye話藍ar;

2, the use of permanent pr資照eservation, the data will be saved to 光少the EEPROM, permanent preservati業畫on.

CTSC-200:

1, the use of built-in capacitor, 錯間about 100 hours;

2, the use of an external battery card科爸, about 2 years;林都

3, the use of p厭媽ermanent preservation, the問事 data will be saved to the 去人EEPROM, permanent preservation.

CTH300 series: pe些聽rmanent preservation.

Second, the power票師 to maintain data capa請朋city:

CPU122, CPU222: 2048 bytes;

CPU124, CPU224: 8192 by一南tes;

CPUI126, CPUI226: 1024舊雪0 bytes;

CTH300: C series has 32K靜志B; H36 has 32KB女低, H35 has 16KB.


EM277A and COTRUST touch sc秒鐘reen communication 紅討problems

problem:

Use the Division I only with 就遠a PPI communication port of the CP木問U, do not buy Siemens original c舊友able in the case, how to她費 achieve the same time wi兵市th the host com電問puter and touch screen嗎內 communication?

solve:

Through the 200CPU物窗 and 277A connection, take the MPI p個山rotocol, MPI communic很如ation line at the end of t技到he open 277A A, B two西店 points, the other end touch th店火e screen commun吃劇ication port, the 照用CPU and the touch screen bau厭暗d rate settings consist能做ent, you can communicate白朋, The EM277A dial addres不綠s is the MPI slave address co身大nfigured for the HMI.懂見 as the picture shows.

 

EM277A與合信觸摸屏通信問題.jpg

其他的注意事(shì)項與觸摸屏與 CPU通訊一樣(yà站雨ng)。

此方案可解決客戶用到我司主機&樂器nbsp;PPI通訊不夠的情況,如用到我司  CPU能線224+或者 CPU224E,由于此 C報學PU隻帶一個  PPI通訊口,可選擇此種(zhǒn是就g)方案一個  PPI口連電腦窗文上下載程序/監控,另外,經(jīng)過(guò)在黃 EM277A的  R道玩S485連  HMI組成遠南(chéng)  MPI網絡。相比于使用西門子&光在nbsp; S7-300編程電纜,需要用到總線轉換器,且西門子&n我火bsp;S7-300編程電纜昂貴,此種(zhǒn拍這g)方案降低了帶來方便的同時(shí)說的有效地降低了成(chéng)本。

CTSC-200 and S7-300MPI com秒務municates

Question: How do I implement MPI commun什光ication between土短 CTSC-200 and S7-300?

 

Solution: CTSC-200 and S7-3跳子00 between the use of MPI comm鄉綠unication, CTSC-200 PLC does not木場 need to write a話醫ny communication-related proced黑內ures, only need to exchan到裡ge data to a continu快什ous V storage area can be, The S7-3亮些00 needs to call the要聽 system functions X_GET (SFC67) and X_水女PUT (SFC68) in OB1 (or Timi窗厭ng Interrupt Organization Bl喝森ock OB35) to enable comm房都unication between S7-300 and C就身TSC-200. When SFC67 and SFC68 農分are called VAR_AD長問DR Parameters fill in the CTSC-200 da術醫ta address area, where to fill i科說n the P # DB1. 見黑× × × BYTE n corresponds to the CTS熱這C-200 V storage area 喝信which VB × × to VB (× × + n綠公) data area.

First of all, acco吧站rding to the har站很dware configuration of S7300,北愛 configure S7300 sta又身tion in STEP7 and月中 download, pay a吧說ttention to CTSC-200 and S7-300 fac算多tory default MPI address is在見 2, so you must first modify日哥 one of the PLC station 得相address, the exam錯中ple program will S城玩7300 MPI address is set to 2, CTSC-鐵照200 address set 3, and separately to S7中是300 and CTSC-20朋就0 communication rate setti他北ngs are consistent, 話笑can be set to 9.6K,河你 19.2K, 187.5K thr科大ee baud rate, the example門件 program Which selected the rate of 19鄉月.2K.

The example progr些書am calls the data read and write functi也關on blocks in OB1: SF會為C67 and SFC68, as shown below:

圖1.jpg

圖2.jpg

圖3.jpg

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