7 Application Instructions API 50-99 3. PLC COM3 RS-485: Associated flags (Auxiliary relays) and special registers (Special D) for communication instructions RS / MODRW and FWD / REV / STOP / RDST / RSTEF when M1177 = ON. DVP-PLC APPLICATION MANUAL 7-109 Flag Function Action M1136 COM3 retain communication settings. Communication settings will be reset (changed) according to the content in D1109 after every scan cycle. Users can set ON M1136 if the communication protocol requires to be retained.
When M1136 = ON, communication settings will not be reset (changed) when communication instructions are being processed, even if the content in D1109 is changed User sets and resets M1320 COM3 ASCII / RTU mode selection. ON : RTU mode, OFF: ASCII mode. M1316 COM3 sending request. Before executing communication instructions, users need to set M1316 to ON by trigger pulse, so that the data sending and receiving will be started. When the communication is completed, PLC will reset M1316 automatically. User sets, system resets M1317 Data receiving ready. When M1317 is ON, PLC is ready for data receiving. System sets M1318 COM3 data receiving completed.
System sets, user resets M1319 COM3 data receiving error. M1319 will be set ON when errors occur and the error code will be stored in D1253 System sets, user resets Special register Function D1038 Delay time of data response when PLC is SLAVE in COM3 RS-485 communication, Range: 0~10,000. (unit: 0.1ms). D1109 COM3 (RS-485) communication protocol. Refer to the following table in point 4 for protocol setting. D1169 The specific end word to be detected for RS instruction to execute an interruption request (I160) on COM3 (RS-485) If the character received is equal to the low byte in D1169, the interrupt I160 will be triggered. Supported communication instructions:
RS D1252 COM3 (RS-485) Communication time-out setting (ms). If users set up time-out value in D1252 and the data receiving time exceeds the time-out value, M1319 will be set ON and the error code K1 will be stored in D1253. M1319 has to be reset manually when time-out status is cleared. D1253 COM3 (RS-485) communication error code D1255 COM3 (RS-485) PLC communication address when PLC is a slave.