A20B-8200-036 PLC控制系統(tǒng)可簡單劃分為三部分:發(fā)訊元件(輸入部分)、記憶網(wǎng)絡(luò)(程序部分)和電氣執(zhí)行元件(輸出部分)。對于用繼電器控制的系統(tǒng),影響系統(tǒng)可靠性的主要因素是中間繼電器組成的記憶網(wǎng)絡(luò)。對于PLC控制系統(tǒng),高可靠性的PLC取代了中間繼電器組成的記憶網(wǎng)絡(luò),克服了機(jī)械動作式中間繼電器可靠性不高的固有毛病,使系統(tǒng)可靠性大為提高。此時,與PLC自身的安全性與PLC輸入、輸出連接的"發(fā)訊元件"和"電氣執(zhí)行元件"的可靠性,己變成影響整個電氣系統(tǒng)可靠性的主要因素。提高"發(fā)訊元件"和"電氣執(zhí)行元件"可靠性的同時,也就提高了PLC的安全性,通常有兩種方法:一種是選用高質(zhì)量的元器件;另一種是對這些故障率較高的元器件進(jìn)行狀態(tài)檢測和故障診斷,但都受硬件條件和經(jīng)濟(jì)條件的影響而限制了應(yīng)用范用。
PLC具有豐富的軟元件(如內(nèi)部計時器、計數(shù)器、輔助繼電器等),因此可以利用它來設(shè)計一些程序,屏蔽輸入元件的誤信號,防止輸出元件的誤動作。實用的方法有(l)采用軟硬件互鎖設(shè)計,防止誤發(fā)訊和誤動作;(2)在輸入輸出端提高配線的可靠性,提高PLC的安全性。
4、中午在食堂,主菜土豆燉雞塊,阿姨一勺舀上來滿滿的全是雞肉,我大喊一聲“阿姨不要抖!”
5、吃過晚飯去樓下超市玩。
只見她手腕順勢一抖,只剩兩塊,阿姨一臉淡定的說:“你。。。你看你,嚇我一跳!”
我。。。
付錢的時候就問老板:杯到了,現(xiàn)在生意好吧?起碼啤酒賣的多了。
老板看了我一眼說道:啤酒是賣的多了,可是TT賣不出去了啊,連衛(wèi)生紙都賣不出去了。
看來杯來了,一家歡喜一家愁??!
EXOR UniOP T10P-133-16-C095
NEW! Uniop programmer display MD00R-02-0045
Exor UniOP Operator Interface CP02R-04-0045
UNIOP SCREEN MD00R-04-0045 MD00R NEW
UNIOP CP01R-04-0045 *USED*
UNIOP MD00R-02-0045 USPP MD00R020045
Exor UniOP Operator Interface CP02R-04-0045 06/00
UniOP Operator Interface MD02R-04-0045
UNIOP CP01R-04-0045 USPP CP01R040045
UNIOP SCREEN MD00R-04-0045 MD00R
UNIOP MD00R-04 NSFP MD00R04
Uniop Operator Interface PLC # CPOZR-04-004J S/N 1990
UNIOP CP02R-04-0021 USPP CP02R040021
UNIOP EF-02-0045 USPP EF020045
UNIOP MD03R-02-0045 USPP MD03R020045
UNIOP MKDF-04-0045 USPP MKDF040045
UNIOP MD01R-02-0042 USPP MD01R0200421
UNIOP MD03R-02-0042 NSPP MD03R020042
UNIOP SCREEN MD02R-04-2442 MD02R-04 MD02R
UNIOP MEDOS 2000 CP05R-04-0045 Free Ship
UNIOP MD01R-02-0045 MD01R MD01R020045 NEW
UNIOP MD00R-04-0045 PROGRAMMER DISPLY / CONTROL
UNIOP SCREEN CP02R-04-1321 CP02R-04 CP02R
UNIOP EK-02 6ZA982-2 OPERATOR INTERFACE NEW EK02
UniOP 9.6" Display HMI Universal Operator Interface Panel EL-25T-0045
Exor UniOP Operator Interface CP02R-04-0045 10/04
UNIOP MD02F-02-0040 USPP MD02F020040
UNIOP MD00R040045 PLC (PLC1276)
EXOR UniOP T10P-133-16-C095
NEW! Uniop programmer display MD00R-02-0045
Exor UniOP Operator Interface CP02R-04-0045
UNIOP SCREEN MD00R-04-0045 MD00R NEW
UNIOP CP01R-04-0045 *USED*
UNIOP MD00R-02-0045 USPP MD00R020045
Exor UniOP Operator Interface CP02R-04-0045 06/00
UniOP Operator Interface MD02R-04-0045
UNIOP CP01R-04-0045 USPP CP01R040045
UNIOP SCREEN MD00R-04-0045 MD00R
UNIOP MD00R-04 NSFP MD00R04
Uniop Operator Interface PLC # CPOZR-04-004J S/N 1990
UNIOP CP02R-04-0021 USPP CP02R040021
UNIOP EF-02-0045 USPP EF020045
UNIOP MD03R-02-0045 USPP MD03R020045
UNIOP MKDF-04-0045 USPP MKDF040045
UNIOP MD01R-02-0042 USPP MD01R0200421
UNIOP MD03R-02-0042 NSPP MD03R020042
UNIOP SCREEN MD02R-04-2442 MD02R-04 MD02R
UNIOP MEDOS 2000 CP05R-04-0045 Free Ship
UNIOP MD01R-02-0045 MD01R MD01R020045 NEW
UNIOP MD00R-04-0045 PROGRAMMER DISPLY / CONTROL
UNIOP SCREEN CP02R-04-1321 CP02R-04 CP02R
UNIOP EK-02 6ZA982-2 OPERATOR INTERFACE NEW EK02
UniOP 9.6" Display HMI Universal Operator Interface Panel EL-25T-0045
Exor UniOP Operator Interface CP02R-04-0045 10/04
UNIOP MD02F-02-0040 USPP MD02F020040