變頻器控制方式特點(diǎn):
其特點(diǎn)是控制電路結(jié)構(gòu)簡單、成本較低,機(jī)械特性硬度也較好,能夠滿足一般傳動(dòng)的平滑調(diào)速要求,已在產(chǎn)業(yè)的各個(gè)域得到廣泛應(yīng)用。但是,這種控制方式在低頻時(shí),由于輸出電壓較低,轉(zhuǎn)矩受定子電阻壓降的影響比較顯著,使輸出大轉(zhuǎn)矩減小。另外,其機(jī)械特性終究沒有直流電動(dòng)機(jī)硬,動(dòng)態(tài)轉(zhuǎn)矩能力和靜態(tài)調(diào)速性能都還不盡如人意,且系統(tǒng)性能不高、控制曲線會(huì)隨負(fù)載的變化而變化,轉(zhuǎn)矩響應(yīng)慢、電機(jī)轉(zhuǎn)矩利用率不高,低速時(shí)因定子電阻和逆變器死區(qū)效應(yīng)的存在而性能下降,穩(wěn)定性變差等。因此人們又研究出矢量控制變頻調(diào)速。
S7-1200通信和程序的特點(diǎn):
S7-1200是西門子的新一代的控制器,在串口通信方面在硬件與軟件方面都與S7-200不同:通訊方面:作為200的升產(chǎn)品,1200不支持DP等應(yīng)用比較廣泛的通訊協(xié)議,但保留了強(qiáng)大的自由口通訊功能;程序方面:引入塊概念,更接近于300,編程方便,尤其是通訊方面的編程(自由口、MODBUS等,一個(gè)塊可以控制多個(gè)驅(qū)動(dòng)器,不同電機(jī)的數(shù)據(jù)存儲(chǔ)在不同的數(shù)據(jù)庫中;硬件方面:S7-1200現(xiàn)有的幾款PLC都可以擴(kuò)展3個(gè)串口通信模板(即可以全部是RS232接口,也可以全部是RS485接口,也可以是兩種接口的組合),而S7-200這不可以進(jìn)行擴(kuò)展,只能用本體上的RS485口,在這一點(diǎn)上功能強(qiáng)了。軟件方面:S7-1200,在編程上與S7-300的編程方法類似,組態(tài)完硬件接口,直接調(diào)用功能塊就可以,非常簡單,不像S7-200需要對SM進(jìn)行操作。S7-1200與S7-300在串口通信比較起來基本上一樣,但在作Modbus的通信時(shí)不需要額外的Dongle來支持。
Siemens 6ES5-482-4UA20/6ES54824UA20 I/O Ver 02, SEALED OFFERS ACCEPTED
Siemens 6ES5-470-4UC12/6ES54704UC12 Analog Output
Siemens 6ES5-460-4UA13/6ES54604UA13
Siemens 6ES5-460-4UA12/6ES54604UA12 Analog Input
Siemens 6ES5-460-4UA11/6ES54604UA11 Analog Input
Siemens 6ES5-455-4UA12/6ES54554UA12
Siemens 6ES5-454-4UA12/6ES54544UA12 SEALED
Siemens 6ES5-451-7LA12/6ES54517LA12, E-Stand Version 06 FACTORY SEALED
Siemens 6ES5-451-4UA14/6ES54514UA14 Digital Output
Siemens 6ES5-441-4UA14/6ES54414UA14 Digital Input SEALED OFFERS ACCEPTED
Siemens 6ES5-430-4UA14/6ES54304UA14 Remanufactured E-Stand 03 NEW Condition
Siemens 6ES5-430-4UA14/6ES54304UA14 Digital Input Sealed OFFERS ACCEPTED
Siemens 6ES5-430-4UA14/6ES54304UA14
Siemens 6ES5-430-4UA12/6ES54304UA12 Input
Siemens 6ES53761AA11/6ES5-376-1AA11 Memory
Siemens 6ES5-312-5CA12/6ES53125CA12
Siemens 6ES5-312-5CA11/6ES53125CA11 Comm Module
Siemens 6ES5-308-3UB11/6ES53083UB11 Interface
Siemens 6ES5-308-3UA12/6ES53083UA12 Interface Unit
Siemens 6ES5-300-5CA11/6ES53005CA11 Interface
Siemens 6ES5-300-3AB11/6ES53003AB11
Siemens 6ES5-101-8UA13/6ES51018UA13 Controller OFFERS ACCEPTED
Siemens 6ES5-100-8MA01/6ES5-100-8MA01 CPU NICE
Siemens 6AV6-613-0AA51-2CA5/6AV66130AA512CA5 Software NEW OFFERS ACCEPTED
Siemens 6AV3-505-1FB12 /6AV35051FB12 Interface
Securitron BPS-24-1 Power Supply, 1 Amp
SEALED Modicon 140DAO84220/140-DAO-842-20
Reliance Electric/Electro Craft/586-012-643/E586/0586-00-012/HD GB/058600012
Reliance Electric S20-204P2C1000/S20204P2C1000
Reliance Electric S20-202P3C1000/S20202P3C1000
Reliance Electric S20-202P3B1000/S20202P3B1000
Reliance Electric 61C-542/61C542 Analog Input, beautiful condition
Reliance Electric 61C-500/61C500 16 Point Input
Reliance Electric 57C421A/57C-421A / 57C421 Pulse Tach Input OFFERS ACCEPTED
Reliance Electric 57C-411/57C411/57C4112E/57C-411-2E
Reliance Electric 57C-410/57C410/0-57C410 Output
Reliance Electric 57C-410/57C410/0-57C410 Output
Reliance Electric 57C409/57C-409 Ser H Analog Input
Reliance Electric 57C409/57C-409 Ser E Analog Input
Reliance Electric 57C409/57C-409 Ser D Analog Input
Reliance Electric 57C404A/57C404/57C-404A/57C404-A
Reliance Electric 57416/0-57416/57416N Remote I/O
Reliance Electric 57412-D/57412D/57412/0-57412-D
Reliance Electric 57409/57-409/0-57409 Ser C
Reliance Electric 57408/57408C/0-57408-C/0-57408
Reliance Electric 57407-4F/57407/0-57407-4F/057407
Reliance Electric 45C-400A/45C400A/45C400/45C-400
Reliance Electric 45C-381B/45C381B/45C381/45C-381-B
Reliance Electric 45C-381/45C381
Reliance Electric 45C-380/45C380
Reliance Electric 45C-364/45C364 Analog Output NICE OFFERS ACCEPTED
Reliance Electric 45C-321/45C321 Power Supply NICE
Reliance Electric 45C-312/45C312 Rack NICE OFFERS ACCEPTED