9 Application Instructions API 150-199 RTU mode (COM3: M1320 = ON, COM1: M1139 = ON): When X0 = ON, MODRW instruction executes the function specified by Function Code H02 PLC1 PLC2, PLC1 sends: “ 01 02 0500 0010 79 0A ” PLC2 PLC1, PLC1 receives: “ 01 02 02 34 12 2F 75 ” PLC data receiving register: Analysis of the read status of PLC2 Y0~Y17: 1234H 5. Relative flags and data registers when COM1 / COM2 / COM3 works as Master: DVP-PLC Application Manual 9-7 Device Status Device Status Device Status Device Status Y14 ON Y15 OFF Y16 OFF Y17 OFF Register Data Descriptions D0 1234 H PLC converts the data in address 0500H ~ 0515H and stores the converted data automatically.
Device Status Device Status Device Status Device Status Y0 OFF Y1 OFF Y2 ON Y3 OFF Y4 ON Y5 ON Y6 OFF Y7 OFF Y10 OFF Y11 On Y12 OFF Y13 OFF Y14 ON Y15 OFF Y16 OFF Y17 OFF COM2 COM1 COM3 Function M1120 M1138 M1136 Retain communication setting COM M1143 M1139 M1320 ASCII/RTU mode selection setting D1120 D1036 D1109 Communication protocol D1121 D1121 D1255 PLC communication address Sending M1122 M1312 M1316 Sending request request D1129 D1249 D1252 Set value for data receiving timeout (ms) Receiving M1127 M1314 M1318 Data receiving completed completed - M1315 M1319 Data receiving error - D1250 D1253 Communication error code M1129 - - Receiving timeout M1140 - - Data receiving error Errors M1141 - - Parameter error.
Exception Code is stored in D1130 D1130 - - Error code (Exception code) returning from Modbus communication