1757-PFBUL050输入模块1757-PFBUL050输入模块1757-PFBUL050输入模块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。MEASUREX51309223-125USPP51309223125KAWASAKI50999-1470R41NSFP509991470R41TexasInstrument500-5016analogoutputmoduleused9ailableASEABROWNBOVERIYT213001-ABUSPPYT213001ABPERCEPTRON9110014USPP9110014ASEABROWNBOVERI52700230USPP52700230TEXASINSTRUMENTSPLC961642USPP961642ASEABROWNBOVERI3HAA3563-AHA/2USPP3HAA3563AHA2Perceptron147SerialBoard495-0102-01093097-002USEDTEXASINSTRUMENTSPLC2223050-0004USPP22230500004PanasonicACServoDriveMSD021P1EA03workingPanasonicACServoDriverMSDA4ACA1A04workingASEABROWNBOVERISI4662708TUSPPSI4662708TPanasonicServoDriverMBDDT2210NIBFreeShipASEABROWNBOVERIACS601-0011-4-​000B1200801USPPACS60100114000​B1ASEABROWNBOVERIDSSR-170USPPDSSR170ALLENBRADLEY1333-BAAUSPP1333BAAASEABROWNBOVERIR58113972USPPR58113972ASEABROWNBOVERIAPSAF-03USPPAPSAF03PERCEPTRON310-0785-055MCABLE(RJ45),NNBPERCEPTRON912-0008USPP9120008NOS!TEXASINSTRUMENTS4POINTPARALLELINPUTMODULE7MT-3007MT300SIEMENS6ES5-391-5AA13USPP6ES53915AA13ASEABROWNBOVERI52603668NSFP52603668ASEABROWNBOVERI57310001-KD/5USPP57310001KD5TexasInstrument500-588412ModuleI/Obase5005884A+TEXASINSTRUMENTSPLC6EA1710-0AA00-​2AA1USPP6EA17100AA002A​A1TEXASINSTRUMENTSPLC505-2590USPP5052590TEXASINSTRUMENTSPLC5TI-5339USPP5TI5339ASEABROWNBOVERI57771224NSFP57771224TEXASINSTRUMENTSPLC505-6408USPP5056408ASEABROWNBOVERI57288001USPP57288001SQUAREDLAF3640032MV10​27USPPLAF3640032MV10​27panasonicacservomotorMDM202A1CWithTsubakiNEWPanasonicMADDT1207003ACServo200-240VACALLENBRADLEY1326AB-B420E-2​1USPP1326ABB420E21ASEABROWNBOVERI3HAA2400-002NSPP3HAA2400002TEXASINSTRUMENTSPLCPM550-410USPPPM550410TexasInstrumentsMod550LoopAccessModulePM550-400ASEABROWNBOVERIYT212001-AMUSPPYT212001AMTexasInstruments500-503132ptLVDCoutput5005031PanasonicACServoMotorMHMD082G1U750WNewinBoxFreeShipASEABROWNBOVERI58116076USPP58116076PanasonicACServoDriverMSDZ011A1A07FreeShipMITSUBISHIA3NMCA24RUSPPA3NMCA24RITESIEMENSND63T900USPPND63T900TI164PROGRAMMABLEPLCTEXASINSTRUMENTS164-1111TRUTZSCHLER9494.70.536.50​1USPP949470536501PanasonicDV83020LE201ACServoMotorDriverwith60daywarrantyTEXASINSTRUMENTSPLC55PL8312000328USPP55PL8312000328MAZAKPD14BUSPPPD14BPANASONICMSDA083D1AACSERVODRIVEASEABROWNBOVERIDSQC266AUSPPDSQC266AASEABROWNBOVERIQHMM101USPPQHMM101ASEABROWNBOVERIYYT-102CUSPPYYT102CPanasonicACServoDriverMBDDT2210053FreeShipEXLARGS30-0305-M***-​EM2-M6NSFPGS300305M***EM2​M6TexasInstrumentsPLC315-DRDCInRelayOutNEWTEXASINSTRUMENTSPLC505-2510USPP5052510SQUARED8538-SEG13-V02​SNSFP8538SEG13V02STEXASINSTRUMENTSPLC325-07NSFP32507TEXASINSTRUMENTSPLC505-4216USPP5054216***ARCPU-700-AUSPPCPU700A)