S7-300 PLC的CPU315-2PN/DP带有PN口，用过ProfInet电缆（工业以太网电缆）可以与上位机进行Modbus TCP通信，上位机发送数据指令给PLC，通过伺服驱动器控制伺服电机达到指定位置。
《 》2011S2 TCP PLC PLC PLC PC PC PLC PC PLC PLC X86 CPU Socket PLC CPU 7 400 PLC PLC 1 CPU socket-bind-listen-accept CP443 9 UR2 212.168.0.19。 Windows XP sp2 read write IP clo 212.168.0.188 Ethereal socket→bind→> connect PLC write I PLC close PLC ource Destination otocol Info 13,966372L,18,0,18 zL,13,0,19 13.959824212.168.0,19 212.168.0.188TCP2000>200 0 Ack=1 win=560 Len=0 M55=140V TcP"20〉2Se=AK=Wn=49LEn=阿5气 13.959865212,168,0,188212.158.0,19cP2010>2000[Ack]seq-1Ack=1kin=64240[ CHECKSUM INCOREECT]Len= Source Destination Protocol Info 44882821680,18 L168,019 TCP 2075> 2000 15YN Seg=0 ACK=0 win=4240 Len=0 M55=1460 W5=0 4.507139212,168,0,19 12,168,Q,198 Es Data transfer PDu 4.507324212.168.0.188 212.168,0.19 COTP DT TPDU (o)(fragment) 4.508932212.168.0.19 212.168.0.138 TCP150-t5a0>2018[AK]5eq=36615Ack-19060in=560Len=0 4.510544212.168.0.188 212.168,0.19 PREs Data transfer PDu 4.511898212.168.0,19 212.168.0.138 TCP i5o-tsap >2018 LACK] Seq=36615 Ack=19119 win=560 Len=0 4.514254212.168.0.19 212.168,0.138 TCP 2000>2075 [SYN, ACK] seq=0 ack=1 win=560 Len=0 M$$=1460 514288212.168.0.188 212.168,013 TCP 2075>2000 [ACK] Seq-1 Ack-1 win=64240 [CHECKSUM INCORRECT] Len=0 4.515245212.168.0.19 212.168.0.138 TCP2000>2075[RsT]5q=1ACk=311003195win=0Len=0 Reset 3f 9e 2 PLC 041900006B。 0X3e0X0419 340· o1994-2012ChinaAcademicJOurnalElectronicPublishingHouse.Allrightsreservedhttp:/www.cnki.net 《 》2011S2 PLC PLC Time Source Destination rotocol Inf 4/0/6(021,168,,19 212,1669,1 TCP TCP Zer wiNdow 2000> 2010 SYNI Se0=0 ACK=0 wIn=0 Len=D MS5=1450 47.027796212,168,3.18 212,168.0,19 TCP 2010>2000 [SYN, ACK] seg=0 Ack=l win=64240 Len=0 MS$=1460 47.029802212,168.3.19 212.168.0.188 TCP 2000>2010 LACK] Seq=1 Ack=l win=560 Len=0 5 PLC PC PLC TCP PLC TCP TCP/IP 2000 o1994-2012ChinaACademicJOurnalElectronicPublishingHouse.Allrightsreservedhttp://www.cnki.net