【正文】 connectivity and thus control the temperature and stability in the settings, the show sent to the other I, and determine whether there is a need for alarm. As measured by the different temperature, so the optional testing ponents will vary, the current hot dual sensors are: Platinum Lao 10 platinum thermocouple, in 1300 ℃ following longterm scope of work, symbols, LB。 nickel chromium nickelsilicon Thermocouple, in the range 50 ~ +1312 ℃, EU symbols, and so on, the temperature sensor output signals are mV and temperature transmitters from mV transmitter and current / voltage of the transmitter, cents V transmitter is the temperature sensor mV mA signal converted into the current, current / voltage transmitter then mV mA current output of the transmitter into a Vvoltage. The 8031 interface circuit are A / D converter, 8155, the alarm settings, ACSSR, such as chips, of which 8155 as the LED and keyboard interface, A / D converter circuit as the temperature measurement of inputs. According to need, A / D converter can be ADC0809 or AD574, ADC0809 and AD574 is different: ADC0809 figures is the number eight, conversion time for the 100 μ s, analog input voltage of the Unipolar 05 V, while the number of AD574 The median can be set to eight can also be set to 12, and no external CLOCK clock, the conversion time to reach 25 μ s, analog output voltage can be Unipolar the 010 V or 020 V, may also be the bipolar 177。 5V or 177。 10V, and here to AD574 as an example. AD574 the VIN and sampling / maintained for VOUT connected, sampling / maintain the working status of the conversion by the end of STS AD574 state control, when the A / D converter is when, STS for the highoutput, the RP, Into a lowlevel, to the sampling / The logic of maintaining control of end, it is to remain in condition to start A / D converter, the conversion after the end, STS into a lowlevel, after the RPinto high, so that Sampling / holder into the sample state. Keyboard display system using 8155 chip control 4 4 matrix keyboard and four Qiduan of digital LED display, in order to achieve the user39。s input and output data. The keyboard of 16 keys for the number keys 09, AF for the function keys, plete set of parameters, the display of choice, automatic / manual conversion, stop and start system. 8155 B of the system will display interface as the mouth, the 74 LS48 drive connected with the LED, 8155 A mouth of the PA3PA0 as scanning interface, from the mouth of the B PB3PB0 read out value, keyboard interrupt way to deal with Therefore, the 8155 B I work in two ways: in the show for the importation of state, the keyboard interrupt service procedures for the importation of processing methods. Singlefrequency alarm can be, in Figure 1, 7406 is the drive, and then in 8031 the mouth, in 8031 to highoutput, low output 7406, the buzzermingthe contrary, Wong buzzer to stop the sound. The temperature control can be isolated with photoelectric trigger a zerotwoway ACSSR SCR to achieve. ACSSR and heating wire series connection in the exchange of power on the 200 V50Hz, ACSSR time can be connected to ACSSR control on a trigger impulse control, with zero detection circuit output by the RP8031 and the output of T0 To trigger ACSSR (hightrigger), if T0 in 1 s, the total for the high, while ACSSR was launched 100 times the maximum power at this time of heating the contrary, if T0 in the total for 1 s LOW, the ACSSR output power of 0, T in a given cycle, as long as the change in ontime ACSSR can change the heater power, to achieve the purpose of regulating temperature. Temperature control procedures to plete the task: 8031,8155 chip initialization and the allocation of memorychip timer and set parameters, temperature sampling, digital filtering, conversion, the judgement of whether the temperature within the specified scope, and overrun the police handling 。 Show that the temperature control and input. The highprecision control system, has a good interactive features, and a supermoderate off dual alarm, a problem can be found immediately, through the automatic adjustment control temperature and the temperature control, temperature control in the settings on the , The normal operation without human intervention, the labor intensity of small operators.中文翻譯單片機在爐溫控制中的應用單片機具有集成度高，運算快速快，體積小、運行可靠，價值低廉，因此在過程控制、數據采集、機電一體化、智能化儀表、家用電器以及網絡技術等方面得到廣泛應用，本文主要介紹單片機在爐溫控制中的應用。 在工業(yè)生產中，有很多行業(yè)有大量的加熱設備，如用于熱處理的加熱爐、用于熔化金屬的坩堝爐，以及各種不同用途的加熱爐，反應爐，這樣溫度就成為了工業(yè)對象中一種重要的被測控對象，但是由于爐子的種類，用途不同，因此，采用的加熱方法及燃料也就不同，如煤氣、天然氣、油、電等，但究其控制系統本身的動態(tài)特性而言，基本上都是一階純滯后環(huán)節(jié)。實踐證明，用于工業(yè)生產中的爐溫控制的微機控制系統具有高精度、功能強、經濟性好的特點，無論在提高產品質量還是產品數量，節(jié)約能源，還是改善勞動條件等方面都顯示出無比的優(yōu)越性。 對于溫度控制，可采用適用于工業(yè)控制的單片機組成的自動控制系統， 其系統被測參數主要是溫度，被測參數溫度值由熱電偶傳感器測定后得到的mV信號經過溫度變送器放大濾波后變?yōu)?－5V的電壓信號，再送到采樣/保持器，經過A/D轉換器后，將模擬信號變?yōu)閿底中盘栠M入8031單片機。在單片機進行數據處理，一方面，與所設定的期望溫度值進行比較后，產生偏差信號，單片機根據預定的PID算法計算出相應的控制量，該控制量控制雙向可控硅的導通和關閉，以便切斷和連通加熱設備，從而控制溫度穩(wěn)定在設定值上，另一方面送去顯示接口，并判斷是否有報警需要。 由于所測的溫度不同，所以選用的檢測元件也就不盡相同，目前的熱點偶傳感器有：鉑鐒10－鉑熱電偶，其可在1300℃以下范圍長期工作，符號LB；鎳鉻－鎳硅熱電偶，測量范圍在－50～＋1312℃，符號EU等等，溫度傳感器輸出的都是mV信號，而溫度變送器由毫伏變送器和電流/電壓變送器組成，其毫伏變送器就是把溫度傳感器的mV信號變換成mA的電流；電流/電壓變送器再把毫伏變送器輸出的mA電流變成V電壓。 8031的接口電路有A/D轉換器，815報警設置、AC－SSR等芯片，其中8155作為LED和鍵盤接口，A/D轉換器作為溫度測量電路的輸入接口。 根據需要，A/D轉換器可采用ADC0809或AD574，ADC0809與AD574不同在于：ADC0809的數字量是8位，轉換時間為100μs，輸入模擬電壓為單極性的0－5V，而AD574的數字量位數可設成8位也可以設為12位，且無需外接CLOCK時鐘，轉換時間達到25μs，輸出模擬電壓可以是單極性的0－10V或0－20V，也可以是雙極性的177。5V或177。10V之間，這里以AD574為例。 AD574的VIN和采樣/保持器的VOUT相連，采樣/保持器的工作狀態(tài)由AD574的轉換結束STS的狀態(tài)控制，當A/D轉換正在進行時，STS輸出為高電平，經反相后，變?yōu)榈碗娖?，送到采?保持器的邏輯控制端，使其處于保持狀態(tài)，開始A/D轉換，轉換結束后，STS變?yōu)榈碗娖?，反相后變?yōu)楦唠娖剑共蓸?保持器進入采樣狀態(tài)。 鍵盤顯示系統采用8155芯片控制44矩陣鍵盤和4個七段數碼管LED顯示，以實現用戶的輸入和數據輸出。鍵盤的16個鍵中0－9為數字鍵，A－F為功能鍵，完成參數設置、顯示方式選擇、自動/手動轉換、系統停止和啟動。 系統中將8155的B口作為顯示接口，經74LS48的驅動器與LED相連，8155的A口的PA3－PA0作為掃描接口，從B口的PB3－PB0讀入列值，鍵盤處理為中斷方式，所以8155的B口工作在兩種方式下：在顯示狀態(tài)時為輸入方式，在鍵盤中斷服務程序處理過程中為輸入方式。 報警部分可采用單頻報警，其中7406是驅動器，，7406輸出低電平，使蜂鳴器鳴音，反之，使蜂鳴器停止鳴音。 對于溫度的控制可通過帶光電隔離的過零觸發(fā)型雙向可控硅AC－SSR來實現。AC－SSR和加熱絲串接在交流200V50Hz的電源上，AC－SSR接通時間可以通過AC