9 Application Instructions API 150-199 9. RTU Mode: When PLC is connected to VFD-S AC motor drives PLC VFD-S, PLC sends: “ 01 10 2000 0002 04 0012 1770 C4 7F ” VFD-S PLC, PLC receives: “ 01 10 2000 0002 4A 08 ” Registers for sent data (sending messages) Registers for received data (responding messages) Program example 12: COM1 (RS-232) / COM3 (RS-485), Function Code H10 1. Function code K16 (H10): Write in multiple Word devices. Up to 16 Words can be written. For PLC COM2 ASCII mode, only 8 words can be written. 2. PLC COM1/COM3 will not process the received data 3.
Take the connection between PLC COM3 and VFD-B for example, the tables below explain the status when PLC COM3 writes multiple Words in VFD-B. (M1320 = OFF, ASCII mode) (M1320 = ON, RTU mode ) If PLC applies COM1 for communication, the below program can be usable by changing: 1. D1109 → D1036: communication protocol 2. M1136 → M1138: retain communication setting 3. D1252 → D1249: Set value for data receiving timeout 4. M1320 → M1139: ASCII/RTU mode selection 5. M1316 → M1312: sending request 6. M1318 → M1314:
receiving completed flag DVP-PLC Application Manual 9-26 Register DATA Explanation D1256 Low 01 H Address D1257 Low 10 H Function D1258 Low 20 H Data Address D1259 Low 00 H D1260 Low 00 H Number of Registers D1261 Low 02 H D1262 Low 04 H Byte Count D1263 Low 00 H Data content 1 The content of register D50 (H12) D1264 Low 12 H D1265 Low 17 H Data content 2 The content of register D51 (H1770 = K6,000) D1266 Low 70 H D1267 Low C4 H CRC CHK Low D1268 Low 7F H CRC CHK High Register DATA Explanation D1070 Low 01 H Address D1071 Low 10 H Function D1072 Low 20 H Data Address D1073 Low 00 H D1074 Low 00 H Number of Registers D1075 Low 02 H D1076 Low 4A H CRC CHK Low D1077 Low 08 H CRC CHK High