AH500 Programming Manual Additional remark: 1. If the value in m or n exceeds the range, the operation error occurs, the instruction is not executed, SM0 is ON, and the error code in SR0 is 16#200B. 2. The flags related to the instruction RS/MODRW: 6-396 Flag Description Action COM1 COM2 SM96 SM97 The data is sent through COM1/COM2. If users want to use the instruction RS/MODRW to send and receive the data, they have to use the pulse instruction to set SM96/SM97 to ON. When the instruction is executed, the PLC sends and receives the data. After the sending of the data is complete, the system automatically resets SM96/SM97 to OFF.
Users set the flag to ON, and the system automatically resets it to OFF. SM98 SM99 When SM98/SM99 is ON, the PLC is waiting to receive the data. The system automatically sets the flag to ON and resets it to OFF. SM100 SM101 Reception through COM1/COM2 is complete. After the receiving of the data is complete, the system automatically sets SM100/SM101 to ON. When SM100 is ON, the data received can be processed. After the processing of the data received is complete, users have to reset SM100/SM101 to OFF. The system automatically sets the flag to ON, and users reset it to OFF. SM102 SM103 An error occurs during the reception of the data by using the instruction MODRW or the instruction RS.
The error codes are recorded in the error logs. The system automatically sets the flag to ON, and users reset it to OFF. SM104 SM105 If users set the communication timeout (in SR210/ SR211, SR213/ SR214) and no data is received after the timeout period, the flag is ON. After the problem is solved, users have to reset SM104/SM105 to OFF. The system automatically sets the flag to ON, and users reset it to OFF. SM106 SM107 The choice between the 8-bit processing mode and the 16-bit processing mode ON: The 8-bit processing mode OFF: The 16-bit processing mode Users set the flag to ON and reset it to OFF. SM108 SM109 Data reception complete flag The receiving of data through COM1 is complete. ON:
when the PLC receives data, it will determine whether there is any interrupt characters (SR621/SR622 low byte). If there is, it will run the interrupt task and then stop receiving data even if there is data that have not been received. OFF: when the PLC receives data, it will determine whether there is any interrupt characters (SR621/SR622 low byte). If there is, it will run the interrupt task and after that it will continue receiving data till the reception is complete. The receiving data length is n (default). Users set the flag to ON and reset it to OFF.