西门子的S7-200的程序结构

  过程映像输入/输出（I/Q）、变量存储器V、内部存储器位M、定时器T、计数器C等属于全局变量。S7-200的程序组织单元(ProgramOrganizationalUnit，简称为POU)包括主程序、子程序和中断程序。每个POU均有自己的64字节局部变量，局部变量只能在它所在的POU中使用。与此相反，全局变量可以在各POU中使用。

  下面是子程序可以使用的局部变量：

  1)TEMP(临时变量)是暂时保存在局部数据区中的变量。只有在执行该POU时，定义的临时变量才被使用，POU执行完后，不再保存临时变量的数值。

  2)IN是由调用它的POU提供的输入参数。

  3)OUT是返回给调用它的POU的输出参数(子程序的执行结果)。

  4)IN_OUT是输入_输出参数，其初始值由调用它的POU传送给子程序，并用同一变量将子程序的执行结果返回给调用它的POU。

  主程序和中断程序的局部变量中只有临时变量TEMP。

  具有输入、输出参数和局部变量的子程序易于实现结构化编程，对于长期生产同类设备或生产线的厂家尤为有用。这些厂家的编程人员为设备的各组件或工艺功能编写了大量的通用的子程序。即使不知道子程序的内部代码，只要知道子程序的功能和输入、输出参数的意义，就可以通过程序之间的调用快速“组装”出满足不同用户要求的控制程序。就好像用数字集成电路芯片组成复杂的数字电路一样。

  子程序如果没有输入、输出参数，它和调用它的程序之间没有清晰的接口，很难实现结构化编程。

  子程序如果没有局部变量，它和调用它的程序之间只能通过全局变量来交换数据，子程序内部也只能使用全局变量。将子程序和中断程序移植到别的项目时，需要重新统一安排它们使用的全局变量，以保证不会出现地址冲突。当程序很复杂，子程序和中断程序很多时，这种重新分配地址的工作量非常大。

  如果子程序和中断程序有局部变量，并且它们内部只使用局部变量，不使用全局变量，因为与其他POU没有地址冲突，不需作任何改动，就可以将子程序移植到别的项目中去。

Siemens BL 3p 15a B315 Bolt In Circuit Breaker
       Siemens B345 BL 3 pole 45 amp Circuit Breaker
       Siemens B335 BL 3 pole 35 amp Circuit Breaker
       Siemens B325 BL 3 pole 25 amp Circuit Breaker
       Siemens B120AF 1p 20a 120v Arc Fault Breaker 1-yr Warranty
       SIEMENS A5E00359595 BOARD A5E00359622 (A11)
       SIEMENS A5E00246214 BOARD (A11)
       Siemens 6EP1 332-2BA00 SITOP Power 4 Power Supply
       Siemens 48DH38A6S2 Bi Metal OL Relay
       Siemens 48ASU3M20 ESP100 Overload Relay Trip Class 20 270 AMP 3 Phase
       Siemens 3SE3 100 -0V AC1 10A
       Siemens 3RV1021-1DA10 Motor Starter 2.2-3.2A BC
       SIEMENS 100 AMP 3 POLE CIRCUIT BREAKER ED43B100 WA-94 FREE SHIPPING!
       PULLOFF SIEMENS SITOP POWER 10 SUPPLY 6EP1-334-1SL11
       LOT OF 9 SIEMENS 6ES7 322-1BH01-0AA0 DAMAGED DURING REMOVAL (D5)
       LOT OF 7 SIEMENS 6ES7 153-2BA01-0XB0 DAMAGED DURING REMOVAL (D5)
       ITE/Siemens ED43B050
       ITE Siemens ED41B045 1 pole 45 amp 277 volt Circuit Breaker
       GE Disconnect, 30 AMP, 20 HP, TH3361 Mod 4.
UN       SIEMENS ITE BQD160 277 VAC 60 A 1 Pole CIRCUIT BREAKER
UN       SIEMENS ITE BQD140 277 VAC 40 A 1 Pole CIRCUIT BREAKER
UN       SIEMENS ITE BQD130 277 VAC 30 A 1 Pole CIRCUIT BREAKER
Un       Siemens 3RT1023-1AK60 Contactor, 9 Amp, 3 Pole, 120 Volt
UN       ITE Siemens QT24020 120/240 VAC 40/20 A 4 (2/2) Pole CIRCUIT BREAKER
UN       ITE SIEMENS EE1B060 60 Amp 120 V 1 Pole CIRCUIT BREAKER
United Electric Type NJ21K Model 7676, 6-73, 0-25 Psi, Shipsameday, ZD#6
Two Siemens 3RV1421-4AA10 Motor Circuit Breakers 10 15 HP
Two Siemens 3RV1011-1JA10 Motor Circuit Breakers 5 HP
TRUMPH SIEMENS DIGITALE PIGGY BACK CIRCUIT BOARD CARD G34924-W1022-C010
Transformator Siemens 4AV 3995-0AA00, prim. 214-425V, sec. 24VDC, 4 Amp.
Trafo Transformator Siemens 4AM4041-5AT10-0C
TOUCHSCREEN GLAS GLASS FüR SIEMENS SIMATIC Panel PC 870 IL70 TOUCHPANEL 6AV7612
TI Texas Instruments U-06B PLC Base Unit U06B Backplane Rack Free Shipping!
TI Siemens CTi RCM-2030 RCM2030 Relay Contact Module PLC
Texas Supervisory Circuits 2.25V, TLC7725ID, 296-3280-5-ND, Lot Of 31, H#64
Texas Instruments/TI/Siemens Simatic 505-4808 120/220 AC Output Module/Card, PLC
Texas Instruments U-04B or Siemens U-04BJ 4 slot rack with 12 month warranty
TEXAS INSTRUMENTS SEMI IC80C517AN18      IC80C517AN18
TEXAS INSTRUMENT/SIEMENS 32 PT 110VAC INPUT MODULE 500-5055
Texas INS IC DRVR/RCVR RS-232, 296-9595-1-ND, MAX3221IDBR, Lot Of 43, E#86
TEC Siemens 550-767N TEC APOGEE FREE SHIPPING
T997 Siemens Simatic 6ES7 332-1BF01-0AA0 E-5
T881 Siemens Sirius 3RS1020-1DD
T69 Siemens Sinec 6GK1543-1AA01 E-5
T68 Siemens Sinec 6GK1543-1AA01 E-4 6GK1 543-1AA01 SPS
T67 Siemens Sinec 6GK1543-1AA01 E-3
T312 Siemens Simatic 6ES7 132-4BF00 Unbenutz versiegelt 6ES7132-4BF00 ET 200S
T1425 Siemens Simatic Eprom 6ES5 374-2KH21 E-1 Memory Card
T1139 Siemens Simatic 6ES7 954-8LC02-0AA0 6ES7954-8LC02-0AA0 FS01 Versiegelt
Surplus Siemens ITE ED41B060 60 amp 1 pole 480 volt Circuit Breaker
Surplus Panel Pullout Siemens BQ2B100 2 pole 100 amp Circuit Breaker
Surplus Panel Pullout Siemens BQ2B090 2 pole 90 amp Circuit Breaker
Surplus Panel Pullout Siemens BQ2B080 2 pole 80 amp Circuit Breaker
Square D FH16020A 125/277V 1 Pole 20 Amp Circuit Breaker (      in Box)
SQUARE D 2510 FW-1P FHP Manual Starter Nema 1 Enclosure Series A
SMC Solenoid NVFS2310-3DZ, NVFS23103DZ, Shipsameday, #1543AR
SM322 ES7-322-1BL00-0AA0 SIEMENS OUTPUT MODULE 32POINT DIGITAL 24VDC
SM321 ES7-321-1BL00-0AA0 SIEMENS OUTPUT MODULE 32POINT DIGITAL 24VDC
Skt Mtr 600V 200A 1Ph 3Wire SIEMENS ENERGY Panel Box Accessories SUAT417-XG
Six (6) Siemens Q22040CT 40-Amp Double Pole Two 20-Amp Single Pole Breaker
SITOR SIEMENS FUSE 3NE4 122
SITOR SIEMENS FUSE 3NE4 121
SITOR SIEMENS FUSE 3NE4 120
SITOR SIEMENS FUSE 3NE4 118
Simens Simatic S5 6ES5491-0LA12 Adaption Casing      !!
Siemens-Schütz,11KW,230V/AC,50Hz,3RT2026-1AP00,OVP,3RT2026-1AP00 3RT
SiemensLOGO!Power 6EP1311-1SH12 E: 01
Siemens-Landis & Staefa RAK122.0021M 55.13225.040 -un      /OVP-
SIEMENS-ITE D11CEU2 rotary handle (NIB)
SIEMENS-ALLIS TA3-K350 *      IN A BOX*
Siemens-Allis Static Trip II Type TI (2T)
Siemens-Allis MSP30L motor starter protector 4-6.3 amp
Siemens-Allis MSP30L Manual Starter Protector
Siemens-Allis MSP30J Motor Starter Protector 2.5-4 Amp
Siemens-Allis Current Limiting Fuse 48FM3R-4 2.4-4.8kV 100 Amp
Siemens-Allis 3ZA2312-1D Limit Switch Top Push Roller Snap Action 24-162-261-501
Siemens-3NP407-Recognized-Fuse-Holder
Siemens: AWD4420-5AD, 8WD4420-5AC and 8WD4420-5AB Stackable Light Set W
Siemens: 49AB01 - Aux. Contact, Side Mount, 1 NC., NEMA Size 00-4, Bundle 7-PACK
SIEMENS/TI 505-7339/5057339 INTERFACE MODULE ***NNB***
Siemens/Simatic 6ES7-194-4CB00-0AA0/6ES71944CB000AA0
SIEMENS/POTTER & BRUMFIELD CB SWITCH W31-X2M1G-10 UN       0615
SIEMENS/ITE/MURRAY Q320 20 AMP 3 POLE 120/240V 3-POLE CIRCUIT BREAKER
SIEMENS/ITE ED23B040 60A 240VAC CIRCUIT BREAKER ***NIB***
SIEMENS/ITE 150 AMP 3P BREAKER QJ23B150 D-27F
SIEMENS/BREGENHORN-BUTOW BOARD 302849-01 TYPE DBM2/X FOR SIPLACE M/N 80S20
Siemens,5SY6325-7,UL1077 SUP. PROT,6KA,3P,25A,C-TRIP
SIEMENS,3RT10241AP00,CONTACTOR, AC-3, 5.5KW/400V
SIEMENS,3RT10151BB42,CONTACTOR, AC-3, 3KW/400V
SIEMENS, TERMINAL BLOCK JUMPERS, 2 POLE, 8WA1895, LOT OF 159
Siemens, Overload Relay #3UA5900-2C, 16 to 25 Amp, 600Volt, 3 Pole, NIB
SIEMENS, LOW TEMP CUTOUT CONTROL RANGE 35/45F, CAT#134-1511,     
Siemens, ITE 25 Amp Circuit Breaker:, Inv 2707
Siemens, ITE 25 Amp Circuit Breaker (2707)
Siemens, GES7-195-7HB00-0XA0, Bus Module,
Siemens, GCA161.1U, Spring Return Electric Damper
SIEMENS, F2020,       , 600V, SIEMENS F2020 20A 600V 2P       
SIEMENS, EE1B015 N,      , 120V, SIEMENS EE1B015 N 15A 120V 1P      
Siemens, Contactor TJ500-0BB4
SIEMENS, CFS361J, 30A, J FUSE PROV. 200KAIC
SIEMENS, CC2-B030 U,       , 277/480V, SIEMENS CC2-B030 U 30A 277/480V 2P       
SIEMENS, CC2-B020 U,       , 277/480V, SIEMENS CC2-B020 U 20A 277/480V 2P       
SIEMENS, AIR DUCT HOUSING FOR SERIES 11, PART#AD-11PC,       IN BOX
SIEMENS, A1106030023, RES, SNBR, NON-IND, 200OHM, I10%
SIEMENS, 8WH3003-0AF00, TERM BLOCK,IDC,THRU-TYPE,2.5,GRAY,3-CONN 50/BX
SIEMENS, 6XV1-850-0BH50, CABLE ITP STANDARD 9/15 5 M
SIEMENS, 6SY70106AA01, NTC THERMISTOR, W98628S1001C24
SIEMENS, 6FX5002-2CD01-1AD0, SIGNAL CABLE, PREASSEMBLED 6FX50022CD011AD0
SIEMENS, 6ES7972-0BB42-0XA0, PROFIBUS CONNECTOR, 12MB, T CBL, PG SOCKET
Siemens, 6ES7 321-1BH02-0AA0, Input Card,       
SIEMENS, 6EP1332-1SH41, POWER SUPPLY 2.5AMP 24VDC
SIEMENS, 5SY6332-6, UL1077 SUP. PROT, 6KA, 3P, 32A, B-TRIP
SIEMENS, 5SQ32701BA16, N-TYPE MCB, 400VAC, 4.5KA, 2-POLE, 16A
Siemens, 5SM3744-6, FI-SCHUTZSCHALTER TYP A 40A,400V, 500MA,
Siemens, 5SM3742-6, FI-SCHUTZSCHALTER TYP A , 25A ,IFN 500MA ,400V
SIEMENS, 52SA7ADN, SELECTOR SWITCH 2-POS LESS LEVER
SIEMENS, 52PT6DAA, PUSH TO TEST PILOT LIGHT FULL VOLTAGE TYP. 24 VOLTS, AC/DC
SIEMENS, 52PT6D5A, PUSH TO TEST PILOT LIGHT
SIEMENS, 52PT6D3AB, PUSH TO TEST PILOT LIGHT FULL VOLTAGE 24 VOLTS AC/DC
SIEMENS, 52PL4L3, PILOT LIGHT, LED MOD 24V, GREEN, PLASTIC
SIEMENS, 52PL4K9, PILOT LIGHT TRANSFORMER TYPE 600VOLTS AC, AMBER
SIEMENS, 52PL4K5, PILOT LIGHT TRANSFORMER TYPE 600 VOLTS, AC, BLUE
SIEMENS, 52PL4G9, PILOT LIGHT TRANSFORMER TYPE 123-130 VOLTS, AC, AMBER
SIEMENS, 52PA2D3A - PUSHBUTTON, MTD, GRN, 1 3/4"MTL ILL, 2POS
SIEMENS, 52PA2D2A, PUSH PULL BUTTON,MTD,RED,1 3/4"MTL ILL,2POS
SIEMENS, 52BP2V2, PUSHBUTTON,MTD,RED,2 1/2" PLASTIC ,2POS
SIEMENS, 3TX4210-0H -- LABEL, TERMINAL STRIP, BLANK, 9X20MM
SIEMENS, 3TF34-0AP6, CONTACTOR
SIEMENS, 3RT1-033-1BB40, CONTACTOR, NONREV, S2, 28A, 24VDC, 3P, SCRW
Siemens, 3RG4601-1AB07, Proximity Switch
SIEMENS, 3LD1218-0TB53, 30A 3P ROTARY DISC SW 3LD12180TB53
Siemens, 192-202, Thermostat
SIEMENS-(LOT OF5)-B120 20 AMP SINGLE POLE 120/240V CIRCUIT BREAKERS-(     )
Siemens Zone Valve Actuator 254-01104 1/2" Valve 2 way NC CV=1 SSB81U
Siemens Zone Valve Actuator 245-00211 1/2" Valve 2 way NC CV=2.5 SSA61
Siemens Zeitrelais 3RP1525-2AP30,230V/AC+24VAC/DC 3RP,NEU,OVP Zeit-Relais
Siemens Zeitrelais 3RP1525-1AP30 GEB
Siemens Zeitrelais 3RP1505-2BW30 24-240V/AC/DC 0,05s-100h NEU, OVP Relais 3 RP
Siemens Zeitrelais 3RP1505-1BW30 24-240V/AC/DC 0,05s-100h NEU, OVP Relais 3 RP
Siemens Zeitrelais 3RP1505-1AP30 GEB
SIEMENS X-RAY GENERATOR CIRCUIT BOARD MODULE 73-51-943 X1423 D121 7351943 X1423
SIEMENS X-RAY GENERATOR CIRCUIT BOARD MODULE 1306-137-55 1306.137.55 1306-136-01
SIEMENS X-RAY CIRCUIT BOARD CARD 83-53-039 X1423 D44 8353039 X1423
SIEMENS X-RAY CIRCUIT BOARD CARD 73-53-782 X1423 7353782 D48
Siemens Wireless Terminals Toshiba T6K03 Display Driver Software Integration Man
Siemens Wire Grip Kit TA1-F350 For F Frame Breaker *Lot of 4*       Surplus
Siemens WINCC FLEXIBLE 2008 RUNTIME Single License/ WinAC RTX 2010 Single Licens
SIEMENS WB3100 Outdoor Breaker Enclosure