spilleravr Posted March 29, 2016 Report Share Posted March 29, 2016 Hello, I want to send 8 bytes of data from a microcontroller to the PLC and display it. I am using a V1040 with a V200-18-E5B snap-in module. I am using MAX232DW IC to convert UART to RS232 from the MCU. At the moment the MCU is sending the following bytes 1 time per second: 0x23 0x05 0x50 0x05 0x50 0x05 0x50 0x05 0x50 0x2B The first byte 0x23 is the start byte and the last byte 0x2B is the end message byte. Do I have to include the start and end byte in the message length? And do I need to do something with the DTR and DSR signals of the RS232 connector? At the moment I am using a 2 meter long 4 pin RJ11 cable, where pins are in the following order - GND, RxD, TxD, GND. So I am sending from the MCU to the PLC's RxD pin and from the PLC to the MCU from the PLC's TxD pin (Sending not implemented yet). The cable is a straight cable. The DIP switches which choose between RS232 and RS485 are set for RS232. I watched the seminar about the FB protocol and made the ladder exactly like that, minus the message. I am expecting to recieved the message above. I have included the project file aswell. The plc does not recieve any messages I am sending. I check with the online "glasses" and the Session byte stays 0 all the time. Does anyone have any idea what could I be doing wrong? Thanks in advance! T COM2_test.vlp Quote Link to comment Share on other sites More sharing options...
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