16. Network Connection Design Examples Note: Maximum 8 special modules are connectible to RTU-485. The first special module connected is the nearest one on the right side of RTU-485. Control Program: z The station No. of RTU-485 is “1”. Write “H’0001” into CR#6 of the 1 st AI/AO special module. Set the communication 300ms Write H0001 into CR#6 of the 1st special module Program Description: z Communication format should be set at the beginning of the program, and the protocal of Master and slave should be the same: 9600 ， 7,E,1 ， ASCII.
z When M0 = ON, the sending request flag will be ON and the master device will send out a request message to RTU-485 and write H’0001 into CR#6 of the 1 st Ai/AO special module on the right side of RTU-485. z For more instructions of communication module RTU-485, please refer to DVP-PLC Application Manual: Special Modules Ⅱ .
DVP-PLC Application Examples 16-13 M1002 MOV H86 D1120 Set th protoc RST M1143 9600, SET M1120 Retain communic Set com MOV K300 D1129 timeout M0 SET M1122 Sending request M0 MODWR K1 H1606 H0001 M1127 Process received data RST M1127 Reset M1127 M1129 Process communicaiton timeout RST M1129 M1140 Process communication error M1141 RST M1140 RST M1141 END END MOV H86 D1120 RST M1143 SET M1120 MOV K300 D1129 SET M1122 MODWR K1 H1606 H0001 RST M1127 RST M1129 RST M1140 RST M1141