与FB相比,FC的局部变量多了一个RET_VAL(返回值)。它实际上是输出参数。默认的情况它是没有数据类型的,在调用FC时也看不到这个输出参数。只要在局部变量表中设置RET_VAL的数据类型,在调用时就能看到它在方框的右边出现,所以它是一个输出参数。
功能FC的英语为Function,也可以像博途那样,将Function翻译为函数。IEC的函数和C语言的函数一样,执行后会产生一个返回值。IEC61131-3的FC也只有一个返回值,不用设置它的名称,返回值的名称和FC的名称相同。因此IEC61131-3的FC只有返回值这样一个输出参数。FANUC ROBOTICS EMERGENCY STOP CONTROL BOARD PCB A16B-12
RELIANCE ELECTRIC S-2000 B79B3194M 3/4 HP PHASE 3 230/4

EUCHNER RIEGEL TZ-CF 076199 SAFETY DOOR BOLT,
MAC 6521B-000-PM-11?1DA 150 PSI 120 VAC SOLENOID VALVE W
CUTLER-HAMMER 13104AQD07 PHOTOELECTRIC SENSOR COMET SER
WAGO 750-600 FREQUENCY ELECTRONIC END BUS,
ALLEN BRADLEY POWER SUPPLY 8520-OFC 160194
NAMCO ET12-23410 PROXIMITY SWITCH LOT OF 9, NIB
TURCK BIM-IKM-AP6X2-H?1141/S34, PROXIMITY SENSOR, 30 VDC
LAMBDA JWS50-24/A 100-240 VAC 50/60 HERTZ POWER SUPPLY,
ROBOHAND RR-36-180-M ROTARY ACTUATOR
SMC D-H7A2 24 VDC PROXIMITY SENSOR, LOT OF 9,
HUBBELL PH2306PB040, CABLE ASSEMBLY, 20 A, 600 VAC, 6 P
BUSSMANN AN250, LIMITER FUSE, LOT OF 5, NNB
ALLEN BRADLEY 800T-N80R ACCESSORY LED LAMP, LOT OF 9, N
INDRAMAT 02.850, CABLE, 35' LENGTH, 9-PIN MALE, 8-PIN F