| 詳細(xì)參數(shù) | |||
|---|---|---|---|
| 品牌 | WESTINGHOUSE | 型號 | 475000 |
| 結(jié)構(gòu)形式 | 模塊式 | 安裝方式 | 控制室安裝 |
| LD指令處理器 | 硬PLC | 功能 | OPTIMAC模擬計算機模塊 |
| 工作電壓 | 電源組24VDC | 產(chǎn)品認(rèn)證 | CE |
| 加工定制 | 否 | 重量 | 19.40磅 |
| 外形尺寸 | 24.00x4.00x7.00 | ||
Westinghouse 475000模擬計算機模塊
無線通訊模組采用中心頻率為433MHz開放的ISM頻段。GRM無線通訊協(xié)議是基于MODBUS開發(fā)的，分為主機協(xié)議和從機協(xié)議，協(xié)議名稱為GRM-ADV，從機按從站號設(shè)置不同進行區(qū)分。GRM102通訊設(shè)置通過巨控模塊配套的開發(fā)配置環(huán)境GRMDEV3進行.
實驗設(shè)置采用一個主機兩個從機的方式，與S7-200連接的GRM102為主機，其他兩個GRM102為從機，主機和從機可以直接雙向通訊，從機之間的通訊可以通過主機進行轉(zhuǎn)發(fā)。
鑒于其控制系統(tǒng)升級的范圍——包括計算機稱重、燃燒器控制和驅(qū)動控制，以及這些其他機會性的改進。在研究了之后，他們決定采用邊緣可編程工業(yè)控制器來實現(xiàn)價值化和功能多樣性?！翱梢灶A(yù)見，各個部分將會融合在一起……當(dāng)意識到可以使用邊緣控制器記錄數(shù)據(jù)時，這為我們打開了另一扇門。一旦找到批次跟蹤數(shù)據(jù)庫通過REST調(diào)用從控制器中提取數(shù)據(jù)的方法，我們就有了一個完整的解決方案。”短短幾個月后，在其中一個現(xiàn)有可編程邏輯控制器（PLC）最終失效之前，就成功將設(shè)計投入使用，而其成本僅為傳統(tǒng)解決方案的一小部分。通過將熔爐生產(chǎn)線的控制器連接到公司數(shù)據(jù)庫，新系統(tǒng)可以將配方管理和工作單跟蹤集成到控制程序和HMI中，這是解決難題的最后一部分。
運行人員不需手動從另一臺計算機上復(fù)制配方參數(shù)，控制器從數(shù)據(jù)庫中查詢適當(dāng)?shù)倪^程量（進料速度、干餾速度、溫度、振蕩周期等），并將其饋送到控制程序。然后，將運行人員輸入的定單信息與從運行中捕獲的過程數(shù)據(jù)一起，記錄到數(shù)據(jù)庫中。
The only problem here is that the process exhibits a varying gain. This is why the control is oversensitive (oscillatory) at high setpoint values and sluggish at low setpoint values. This could be a function of process dynamics, or of a control valve with the wrong characteristic (e.g. an equal-percentage valve in an application better suited for a linear valve).
The controller tuning looks really good when the process variable is maintaining around 40%. This mid-range is where the tuning seems to be optimized.
This process appears to be self-regulating with short dead and lag times. It is b from examining the phase shifts of output versus PV that there is some derivative b at work here, since the output actually leads the PV when there is oscillation. The key will be linearizing the process gain so that one set of tuning beters will work robustly across the control rangehis increases installation costs and permanent pressure loss, which may not be acceptable for some applications. For this reason, flow meter rangeability should be considered from application maximum or process flow maximum, not the meter’s maximum specified flow rate.It is also important to understand how the max to min flow ratio relates to percent of the flow range.
Figure shows the relationship between rangeability and percent of maximum flow. Notice that 10:1 rangeability will measure down to 10% of maximum flow. A meter with 20:1 rangeability will measure down to 5% of maximum flow; only 5% more of the flow range.
