7 Application Instructions API 50-99 6. When RS instruction is in use, the frequently used communication format in the peripheral device will define the start word and end word of the control string. Therefore, you can set up the start word and end word in D1124 ~ D1126 for COM2 or use the start word and end word defined by the PLC. When you use M1126, M1130 and D1124 ~ D1126 to set up the start word and end word, b8 ~ b10 of D1120 have to be set as 1 to make valid the RS-485 communication protocol. See the table below for how to set up. 7. Example of how to set up the communication format of COM2: Assume there is a communication format: Baud rate 9600 7, N, 2 STX : “:” ETX1 : “CR” ETX2 :
“LF” Check the table and obtain the communication format H788 and write it into D1120. b15 b0 D1120 0 Don t care 7 8 8 M1002 When STX, ETX1 and EXT2 are in use, please be aware of the On and Off of the special auxiliary relays M1126 and M1130. 8. D1250 (COM1)/D1253 (COM3) communication error code: DVP-PLC APPLICATION MANUAL 7-112 M1130 0 1 M1126 D1124: user defined D1125: user defined D1126: user defined D1124: H 0002 D1125: H 0003 D1126: H 0000 (no setting) 0 D1124: user defined D1125: user defined D1126: user defined D1124: H 003A (’:’) D1125: H 000D (CR) D1126:
H 000A (LF) 1 0 0 0 0 0 1 1 1 1 0 0 0 1 0 0 0 MOV H788 D1120 Value Error Description H0001 Communication time-out H0002 Checksum error H0003 Exception code exists H0004 Command code error / data error H0005 Communication data length error