1769-OV32T***1769-OV32T***1769-OV32T***PLC点阵键盘在工控行业中，有时候会碰到因为可编程控制器（PLC）输入点的不够，而导致需要更换设备，浪费资源。对此，当实时性不需要那么高时，我们可以编写一个键盘的扫描程序来扩展输入的点数。因为扫描的方式是循环扫描，所以在实时性方面会有一定的欠缺。下面是用海为PLC编程软件编写的8乘6的48键扫描程序。需要用到8个输入点，6个输出点，硬件连接如下图所示：注：当要求实现组合按键时上图的二极管必须加，反之二极管可加可不加。扫描的点是令Y0~Y5循环输出，当有按钮按下时，就会做出相应的动作，例如：当按钮键0按下时，则X0接通，当程序扫描到Y0时，X0与Y0形成一个回路，表示按键“0”按下。程序如下图所示：结论：键盘是以循环扫描的方式来进行输入，而扫描的时间越短则实时性越好。但是当扫描时间过短时会因Y0~Y5输出结束时，X0仍未接通导致无法产生输出信号。或者当Y0输出结束，Y1也输出结束时，X0仍未断开，导致误判断。经过型号SW-S32ZS220T测试可知每次循环扫描的时间T0不得低于20ms。建议可将滤波时间设得短一点，则可以缩短每次循环扫描的时间T0，例如：本例中将滤波时间设为0.8ms，则每次循环扫描的时间T0可以设到***短10ms。PanasonicACServoDriverMSD083A1XXVASEABROWNBOVERI58095141NSFP58095141ASEABROWNBOVERIACS601-0060-4-​000B1200801USPPACS60100604000​B2PanasonicACServoMotorM***042A1GFreeShipASEABROWNBOVERIMHB63700LNSFPMHB63700LPERCEPTRON911-0053USPP9110053TEXASINSTRUMENTSMODEL500-5053PEERLINKINTERFACEASEABROWNBOVERIACH401600532-A​CE0000NSFPACH401600532AC​E0SIEMENS6FX1-120-2CA00USPP6FX11202CA00TEXASINSTRUMENTSDIGITALOUTPUTUNITMODEL#500-5013!ALLENBRADLEY8000-MB2NSFP8000MB2ALLENBRADLEY500-EOD930NSFP500EOD930SIEMENSTI545PLCrackusedTI5451102CPUMODICON610-MSA-210-30USPP610MSA21030TEXASINSTRUMENTSPLC945940-0001-ACUSPP9459400001ACPanasonicACServoDriverMCDDT3520052750WFreeShipYASKAWAELECTRICJANCD-SV03BNSPPJANCDSV03BASEABROWNBOVERIE-32215NSPPE32215PERCEPTRONCAMERATRICAMCONTOURSENSOR911-0007PanasonicACServoDriverMSDA5A3D2A52FreeShip(AG01)PANASONICM***021ABFACSERVOMOTORWORKINGSIEMENS6SN1118-0DA11-​0AA0NSPP6SN11180DA110A​A0TexasInstruments500-5056FISHERROSEMOUNT895CNSPP895CTEXASINSTRUMENTSPLC505-5417NSPP5055417FANUCA06B-6058-H005USPPA06B6058H005ASEABROWNBOVERI086370-001NSFP086370001TEXASINSTRUMENTS5TI-1034-2SEQUENCERMODULE***XLNT***TEXASINSTRUMENTSPLC2261690-1-AAUSPP22616901AATEXASINSTRUMENTSPLCVPU-200-3104USPPVPU2003104GENERALELECTRIC193W-532ACG06USPP193W532ACG06DEZURIKP2000USPPP2000BOSCHB830-303074NSPPB830303074ASEABROWNBOVERI126620-004USPP126620004EXLARGS30-0305-M***-​EM2-M6NSFPGS300305M***EM2​M6PanasonicMFA020LE2NSCACServoMotorwith60daywarrantyTEXASINSTRUMENTSPLC500-5840USPP5005840PANASONICAMKB400B20KAHACSERVOMOTORNEWTEXASINSTRUMENTSPLC560-2123USPP5602123TexasInstruments14SlotRackBase500-5848#23931ASEABROWNBOVERIEHDB520M2P-1LNSFPEHDB520M2P1LALCATEL210SDMLAMNSFP210SDMLAMMITSUBISHIFR-A220E-5.5K-​ULNSFPFRA220E55KULTEXASINSTRUMENTSPLC505-4317NSFP5054317ASEABROWNBOVERIQK-190-0R6501USPPQK1900R6501PanasonicACServoDriverMSDA041A1A100-115V400W(J)SiemensSimaticTI305-02BProgrammableControllerPLCPanasonicACServoDriveMQDB012AAD02NEW0190-15328VAISALASENSORSYSMMT337NSPPMMT337ASEABROWNBOVERIDSDP-140AUSPPDSDP140APanasonicACServoDriverMDD103A2VFreeShipTEXASINSTRUMENTS500-2151-APOWERSUPPLY5002151AFISHERROSEMOUNTCL7001-A10USPPCL7001A10ASEABROWNBOVERIACH501-010-4-0​0P2USPPACH501010400P2TEXASINSTRUMENTS500-5114A**FISCHER&PORTER53MC2112A1XBX1USPP53MC2112A1XBX1ALLENBRADLEY2711-K6C8USPP2711K6C8NEWSEALTISiemens575-21045752104VMEPLCCPUACCURAY18383-004USPP18383004PANASONICSERVODRIVEMSDA013A1ATEXASINSTRUMENTSSiemensTIPN560-2128ASEABROWNBOVERIYB560103-AC/8USPPYB560103AC8TexasInstrumentsPM550-210PowerSupply(AS-IS))