| 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(jì)算機(jī)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(jì)算機(jī)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(jī)協(xié)議和從機(jī)協(xié)議，協(xié)議名稱為GRM-ADV，從機(jī)按從站號設(shè)置不同進(jìn)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(jìn)行.
實(shí)驗(yàn)設(shè)置采用一個(gè)主機(jī)兩個(gè)從機(jī)的方式，與S7-200連接的GRM102為主機(jī)，其他兩個(gè)GRM102為從機(jī)，主機(jī)和從機(jī)可以直接雙向通訊，從機(jī)之間的通訊可以通過主機(jī)進(jìn)行轉(zhuǎn)發(fā)。
鑒于其控制系統(tǒng)升級的范圍——包括計(jì)算機(jī)稱重、燃燒器控制和驅(qū)動(dòng)控制，以及這些其他機(jī)會性的改進(jìn)。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(shí)現(xiàn)價(jià)值化和功能多樣性?！翱梢灶A(yù)見，各個(gè)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(shí)，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(gè)完整的解決方案?！倍潭處讉€(gè)月后，在其中一個(gè)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(jì)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(yùn)行人員不需手動(dòng)從另一臺計(jì)算機(jī)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(jìn)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(yùn)行人員輸入的定單信息與從運(yùn)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.
