描述
在设计梯形图程序时,经常遇到一些需要多次重复的操作,如果一次一次地编程,显然是非常繁琐的。我们常常采用循环的方式来设计功能表图和梯形图,如图5-34所示,假设要求重复执行10次由步S33和步S34组成的工艺过程,用C0控制循环次数,它的设定值等于循环次数10。每执行一次循环,在步S34中使C0的当前值减1,这一操作是将S34的常开触点接在C0的计数脉冲输入端来实现的,当步S34变为活动步时,S34的常开触点由断开变为接通,使C0的当前值减1。每次执行循环的最后一步,都根据C0的当前值是否为零来判别是否应结束循环,图中用步S34之后选择序列的分支来实现的。假设X4为“1”,如果循环未结束,C0的常闭触点闭合,转换条件满足并返回步S33;当C0的当前值减为0,其常开触点接通,转换条件满足,将由步S34进展到步S35。
在循环程序执行之前或执行完后,应将控制循环的计数器复位,才能保证下次循环时循环计数。复位操作应放在循环之外,图5-34中计数器复位在步S0和步S25显然比较方便。
欧美品牌停产的,常用的“PLC”备品备件
我司产品应用于以下领域:
1,《发电厂DCS监控系统》
2,《智能平钢化炉系统制造》
3,《PLC可编程输送控制系统》
4,《DCS集散控制系统》
5,《智能型消防供水控制系统》
6,《化工厂药液恒流量计算机控制系统》
7,《电气控制系统》造纸,印染生产线,变电站综合自动化控制系列
本特利,英维思,伍德沃德,福克斯波罗、西屋、瑞恩、施耐德莫迪康、ABB、AB、西门子、摩托罗拉、GE发那科、安川、博世力士乐,ACSO,力士乐等各大品牌的DCS系统配件,机器人系统配件,大型伺服系统备件。
Woodward 8236-043 Interface 43027
Woodward 8236-144 Light Panel
Woodward 8236-144D Light Panel
Woodward 8238-002 505E Bulkhead
Woodward 8238-007 505 Bulkhead
Woodward 8238-008 505 Flush Mount
Woodward 8238-009 505E Bulkhead
Woodward 8239-001 DSM Synchronizer
Woodward 8239-002 DSM Synchronizer
Woodward 8239-005 DRFD
Woodward 8239-006 Digital Remote Final Driver
Woodward 8239-007 Digital Remote Final Driver
Woodward 8239-008 Digital Remote Final Driver
Woodward 8239-015 Digital Remote Final Driver
Woodward 8239-016 DRFD CONTROL ASSEMBLY
Woodward 8239-939
Woodward 8240-084 EGB10C governor
Woodward 8250-022 remote servo
Woodward 8250-226 EG10P p/n A8250-226
Woodward 8250-421 EG3P oil motor
Woodward 8250-501 actuator
Woodward 8250-570
Woodward 8250-807 TA-20 Actuator
Woodward 8250-818 Governor
Woodward 8256-021 EPG Actuator
Woodward 8270-092 EG-A Control Box
Woodward 8270-122 2301 Power Supply,p/n
Woodward 8270-201
Woodward 8270-741 MOTOR OPERATED POTENTIOMETER
Woodward 8270-758 2301 SIGNAL CONVERTER
Woodward 8270-768 2301 AMPLIFIER
Woodward 8271-147 Load Sensor
Woodward 8271-467 2301 Load Share and Speed Control
Woodward 8271-472 2301 Load Sharing&Speed Control
Woodward 8271-652 2301 Load Share and Speed Control
Woodward 8271-674 Power Supplies
Woodward 8271-872 Import/Export Control
Woodward 8272-385 SPM Synchronizer
Woodward 8272-394 Real Power Sensor
Woodward 8272-447 Motor Operated Pot
Woodward 8272-464
Woodward 8272-684
Woodward 8272-684
Woodward 8272-695 Real Power Sensor
Woodward 8272-720 Real Power Sensor
Woodward 8272-781A Real Power Sensor
Woodward 8273-041 ATLAS SC
Woodward 8273-276 377A7823P001,Atlas PC 2×4 Sc w/act,LV
Woodward 8280-071 Hydraulic Pump
Woodward 8280-415 Digital Speed Control
Woodward 8280-505 723 Plus
Woodward 8290-195 Flo-Tech Speed Control
Woodward 8291-020 EHPC
Woodward 8301-633 MicroNet
Woodward 8405-020
Woodward 8406-113 EGCP-3 DIGITAL CONTROL
Woodward 8406-121 EGCP-2
Woodward 8434-246 Main Chassises w/LED&P.B
Woodward 8512-135
Woodward 8516-038
Woodward 8516-039 TG 13
Woodward 8516-042 4000 RPM CCW
Woodward 8516-051 TG-13E,4000 RPM,CCW MS CONN
Woodward 8516-068 TG-13E Actuator,Pressure Drive
Woodward 8516-076 TG-13A
Woodward 8570-412 PG Dial Governor,p/n C8570-412
Woodward 8575-241
Woodward 8575-377
Woodward 8580-064 Tachometer CIT Sensor
Woodward 8580-069 On Engine Gearbox Hydraulic Pump for Metering Valves
Woodward 8580-071 Engine Gearbox Hydraulic Pump
Woodward 8580-085 Engine Gearbox Hydraulic Pump
Woodward 8580-086 Hydraulic Pump
Woodward 8900-067 Sensor
Woodward 8901-457 CPC
Woodward 8901-881 Fuel/Water Valve
Woodward 8904-289 Valve
Woodward 8904-484 Gas Shutoff Valve with Suppression
Woodward 8904-773 Control 8904-881,9902-002
Woodward 8915-004 1907 Liquid valve with TM-55 Actuator
Woodward 8915-005 3103 Gas Valve with TM-55 Actuator
Woodward 8915-011 Control Valve-TM55P/3103 Low Temp Gas Fuel
Woodward 8915-024 Liquid Fuel Valve
Woodward 8915-046 Control Valve-TM55P/1907 Liq
Woodward 8915-075 Control Valve-TM40LP/3151A Water
Woodward 8915-094 Control Valve-TM55P/3103 High Temp Gas Fuel
Woodward 8915-103 Control Valve-TM40/Liquid LP
Woodward 8915-111
Woodward 8915-1146 3103/EM35 GAS VALVE