描述
从工作方式上看，在继电器控制电路中，当电源接通时，电路中所有继电器都处于受制约状态，即该吸合的继电器都同时吸合，不该吸合的继电器受某种条件限制而不能吸合，这种工作方式称为并行工作方式。而PLC的用户程序是按一定顺序循环执行，所以各软继电器都处于周期性循环扫描接通中，受同一条件制约的各个继电器的动作次序决定于程序扫描顺序，这种工作方式称为串行工作方式。
Parker PRDM2PP02LNM, Pressure Reducing Valve NEW
PARKER 626092 OILDYNE PRESSURE SWITCH 0E4-SBKS-44K NEW
PARKER HYDRAULIC PRESSURE REDUCING VALVE PRDM2PP16LNS
PARKER PRDM2PP16SVGX797 PRESSURE REDUCING VALVE NIB
PARKER MODEL A4A PRESSURE REGULATOR 2 1/2″ NEW
PARKER PRM3PP25K HYDRAULIC PRESSURE CONTROL VALVE
Parker Flo-Con By-Pass Pressure Regulator SM080128 NIB
Parker Pressure Filter F3-15P-1-40SA-ES-50-XX-11-80
Parker 41975 20-20 Clamp SAE flange high pressure
Parker PRM3PAH-20GB Pressure Reducing Valve
Parker PR400SHV Pressure Reducing Valve
NOS! PARKER REMOTE PRESSURE AIR VALVE CWJ12501
NEW Parker Hydraulic Filter 932630Q High Pressure
Parker D39DW11C4N89 75, PRESSURE REGULATION VALVE , NEW
PARKER VERIFLO IR400S4PG PRESSURE REDUCING REGULATOR
