描述
在继电器控制线路中，当电源接通时，线路中各继电器都处于受制约状态，该合的合，该断的断。而在PLC的梯形图中，各“软继电器”都处于周期性循环扫描接通中，从客观上看，每个“软继电器”受条件制约，接通时间是短暂的。也就是说继电器在控制的工作方式是并行的，而PLC的工作方式是串行的。
GE Feeder Protection Relay SR 735-CASE
Ref: GE Feeder Protection Relay SR 735-CASE
GE 12IBC51M1A/IBC51M1A OVERCURRENT RELAY DIRECTIONL*NIB
Ref: GE 12IBC51M1A/IBC51M1A OVERCURRENT RELAY DIRECTIONL*NIB
1 NIB GENERAL ELECTRIC JBC53P1A JBC 53P1A DS RELAY
Ref: 1 NIB GENERAL ELECTRIC JBC53P1A JBC 53P1A DS RELAY
**NIB** GE Overload Relay RTN3F
Ref: **NIB** GE Overload Relay RTN3F
GE 124Y0E2804B Time Delay Relay 600VAC/DC NOS NEW NNB
Ref: GE 124Y0E2804B Time Delay Relay 600VAC/DC NOS NEW NNB
GE General Electric Hand reset Aux relay 12HEA11C46
Ref: GE General Electric Hand reset Aux relay 12HEA11C46
GE Multilin 565-5-5-O-A Feeder Management Relay 565B
Ref: GE Multilin 565-5-5-O-A Feeder Management Relay 565B
GE 12IAC53A803A/IAC-53A803A OVERCURRENT RELAY **NIB**
Ref: GE 12IAC53A803A/IAC-53A803A OVERCURRENT RELAY **NIB**
GE FANUC IC660EBR101L ELECTRIC MODULE RELAY ***RFB***
Ref: GE FANUC IC660EBR101L ELECTRIC MODULE RELAY ***RFB***
GE Time Overcurrent Relay Meter Model 12IAC51B4A, 4 EA.
Ref: GE Time Overcurrent Relay Meter Model 12IAC51B4A, 4 EA.
GE 12IFC66BD1A Long Time Overcurrent Relay IFC66BD1A
Ref: GE 12IFC66BD1A Long Time Overcurrent Relay IFC66BD1A
12XCA28A , GE RELAY TEST PLUG
