初研制生产的 PLC 主要用于代替传统的由继电器接触器构成的控制装置，但这两者的运行方式是不相同的：继电器控制装置采用硬逻辑并行运行的方式，即如果这个继电器的线圈通电或断电，该继电器所有的触点(包括其常开或常闭触点)在继电器控制线路的哪个位置上都会立即同时动作。

BARKSDALE, B1T-A12SS, PRESSURE SWITCH, CSA 3 & 4, 300 V

DWYER 1824 0 WP PRESSURE SWITCH NIB

PARKER 451-1/4S2-125 IN-LINE CHECK VALVE, 5000 PSI, 1.6

SMC AMJ5000-N06B VACUUM DRAIN FILTER, 1.0 MPA (145 PSI)

NSK 30TAC62BSUC10PN?7B SUPER PRECISION BEARING ? SET, NI

ORIENTAL MOTOR VEXTA 120W BRUSHLESS DC MOTOR FBLM5120W-

GREENLEE 60117 DRAW STUD LOT OF 2 NIB

ALLEN BRARLEY 700-HSV1 RELAY LOT OF 3 IN BAG

NEMIC LAMBDA 24V 5A DC POWER SUPPLY HKR-120-24

ALLEN-BRADLEY 872C-D5NP18-N4 INDUCTIVE PROXIMITY SENSOR

HUMPHREY 500AE1310 SOLENOID AIR VALVE, 24 VDC, 6.7 W, 0

WATTS CA-FP-1 CLOSET CARRIER FACE PLATE ASSEMBLY, NIB

WATTS CA-FP-1 CLOSET CARRIER FACE PLATE ASSEMBLY, NNB

HONEYWELL, Q5001D 1018, VALVE BRACKET AND LINKAGE, STRO

RTA PAVIA GMH 06 STEPPER DRIVE

MORLAN FLEX-CORE TRANSDUCER CT5-005E