在選擇方案時(shí)，應(yīng)考慮盡量減少控制元件數(shù)、接點(diǎn)數(shù)和焊點(diǎn)數(shù)，以降低系統(tǒng)的失效率。采用可編程控制器（PC）來(lái)代替由繼電器等組成的控制柜可以提高系統(tǒng)的可靠性。在比較可編程序控制器和繼電器控制柜兩種方案時(shí)，除了購(gòu)置價(jià)格以外，還應(yīng)充分估計(jì)前者在提高可靠性、縮短開(kāi)發(fā)周期和減小工作量以及節(jié)省維修時(shí)間等有利因素。
PLC控制可靠性是指PLC與其被控對(duì)象結(jié)合，組成系統(tǒng)的可靠性。系統(tǒng)的目的也是在規(guī)定的條件下與規(guī)定的時(shí)間內(nèi)，所能完成的規(guī)定功能。本文簡(jiǎn)要介紹了PLC自動(dòng)控制系統(tǒng)的應(yīng)用，分析了PLC控制系統(tǒng)的可靠性設(shè)計(jì)方法，并探討了提高PLC自動(dòng)控制系統(tǒng)可靠性的有效途徑。
JOHNSON CONTROLS V46AB-1 1/2IN NPT WATER REGULATING VALVE 70-260PSIG SIZE 81507
Johnson Controls V46AB-1 Pressure-Actuated Water-Regulating Valve New
JOHNSON CONTROLS V46AB-1C NSFP V46AB1C
NEW JOHNSON CONTROLS PENN V46AB-9510 NIB WATER VALVE 1/2"
From China
Parker A5LB2127AB6A46 Solenoid Valve Direct Acting 120V 60HZ ! NEW !
From Canada
NEW! Johnson Controls PENN V46AB Water Valve 1/2" NPT 70-260 PSIG (S48G)
NIB JOHNSON CONTROLS V46AD-1C WATER VALVE 1'' ALL RANGE 70/260 PSIG V46AD1C
Daikin Pump V38A 1RX-80 _ V38A 1RX-8O _ V38A1RX80 _ AB-26092 _ AB26092 _AB-26O92
JOHNSON CONTROLS V46AD-1 USPP V46AD1
JOHNSON CONTROLS V46AD-1 NSPP V46AD1
JOHNSON CONTROLS V46AD-1 NSFP V46AD1
JOHNSON CONTROLS V46AR-1 NSPP V46AR1
LITTELFUSE 523-5AB-1A-250V NSPP 5235AB1A250V
NEW 1PCS 6SY7010-0AB58 SIEMENS MODULE 6SY70100AB58
From Malaysia
NEW 1PCS WESTCODE MODULE 6SY7010-0AA52 6SY70100AA52
From Malaysia
NEW 1PCS WESTCODE MODULE 6SY7010-0AA54 6SY70100AA54
From Malaysia
NEW 1PCS WESTCODE MODULE 6SY7010-0AA40 6SY70100AA40
From Malaysia
NEW 1PCS WESTCODE MODULE 6SY7010-0AA41 6SY70100AA41
From Malaysia
1 Pcs 6SY7010-0AA54 WESTCODE MODULE
SIEMENS THYRISTOR MODULE 821A 3PH 380-460V 6SY7010-0AB02 NEW W/ COSMETIC DAMAGE
1 Pcs 6SY7010-0AA40 WESTCODE MODULE
1 Pcs 6SY7010-0AA41 WESTCODE POWER MODULE
1 Pcs 6SY7010-0AA52 WESTCODE POWER MODULE
CUTLER HAMMER 1755K-PMPP-1700 USPP 1755KPMPP1700
CUTLER HAMMER 1775K-PMPP1700 OPERATOR PANEL FOR PARTS
From Canada
PANELMATE CUTLER HAMMER POWER PRO 1785K PMPP 1700 1785K-PMPP-1700 1785KPMPP1700
Cutler-Hammer 1775K PMPP1700 PanelMate "Exchange"
From Germany
Siemens I-T-E Type ED6 Circuit Breaker, 100 AMP - 600 Volt AC / DC
CC LINK COMMUNICATIONS MODULE, MITSUBISHI FR-E5NC
MITSUBISHI FR-E5NC USPP FRE5NC
MITSUBISHI FR-A5NC USPP FRA5NC
SAJF// MITSUBISHI FR-A7NC-E KIT FREQROL E700 INVERTER NEW
From Korea, South
Mitsubishi FR-A5NC CC Link Communication Option NEW
C500-NC103-E Omron PLC Motion Module 3G2A5-NC103-E C500NC103E 3G2A5NC103E
GOULD / MODICON C489 REV D NC1 FR-0 DPC-5
Mitsubishi Freqrol-A200 FR-A240E-3.7K-UL 5HP Inverter FR-PUO2E-1 Parameter Unit
MITSUBISHI E500 INVERTER AC DRIVE CAT#FR-E540-3.7K-NA 5HP 9.5A 3PH 400Hz
Mitsubishi E500 FR-E540-3.7K-NA Inverter 5 HP Input 3 Ph
NIB Mitsubishi Devicenet Option for E540 FR-E5ND
MITSUBISHI INVERTER E700 FR-E720-050-NA FR720050NA INPUT 200-240V OUTPUT 5 AMP
PEPPERL+FUCHS KFA5-DWB-Ex1.D ISOLATED AMPLIFIER 188381
PEPPERL & FUCHS KFA6-SR2-EX1.W USPP KFA6SR2EX1W
PEPPERL & FUCHS KFA6-SR2-EX1.W.LB USPP KFA6SR2EX1WLB
PEPPERL & FUCHS KFD2-DWB-EX1.D USPP KF