9 Application Instructions API 150-199 12. The functions of S 3 , S ,and n vary with the function code used. 13. There is no limitation on the times of using this instruction. However, only one instruction can be executed at a 14. Rising-edge contact (LDP, ANDP, ORP) and falling-edge contact (LDF, ANDF, ORF) can not be used as drive time. contact of MODRW (Function code H02, H03, H04, H17) instruction, otherwise the data stored in the receiving registers will be incorrect. 15. MODRW instruction determines the COM port according to the communication request. The COM port determination is made following the order: COM1 COM3 COM2.
Therefore, please insert every MODRW instruction right after the sending request instruction for avoiding errors on the target location for data access. 16. For detailed explanation of the associated flags and special registers, please refer to the remarks on API 80 RS instruction.
DVP-PLC Application Manual 9-3 Communication Model H02 H03 H04 H0F H10 H17 mode COM1 ASCII Mode (M1139 Off) EH3 SV2 K256 K24 K24 K256 K24 K24 COM2 RTU Mode (M1143 On) ES Not supported K16 Not supported Not supported K16 Not supported SA K64 K16 K16 K64 K6 K16 EH/EH3/SV2 K256 K16 K16 K256 K16 K16 COM2 ASCII Mode (M1143 Off) ES Not supported K8 Not supported Not supported K8 Not supported SA K64 K8 K16 K64 K8 K16 EH/EH3/SV2 K256 K16 K16 K256 K16 K16 Function S 3 S n code H02 Address from which data is read Register where data read is stored Number of data read H03 Address from which data is read Register where data read is stored Number of data read H04 Address from which data is read Register where data read is stored Number of data read H05 Address into which data is written None State value written H06 Address into which data is written Data register where data written is stored None H0F Address into which data is written Data register where data written is stored Number of data written H10 Address into which data is written Data register where data written is stored Number of data written H17 S :
Address from which data is 3 read S +1:Address into which data 3 is written S: Register where data read is stored S+1: Data register where data written is stored n: Number of data read n+1: Number of data written