2 Functions of Devices in DVP-PLC 7. Note: a) PLC LINK is based on Modbus communication protocol. b) EH2/SV/EH3/SV2 supports 32 stations in the LINK and reading/writing of more than 16 data (SET1353) (M1353 = On). SA/SX/SC supports 16 devices in the LINK and reading/writing of 16 data. c) EH2/SV/EH3/SV2: When a MASTER PLC and a Slave PLC is connected, they are able to read/write maximum 100 WORD data (M1353 = On). SA/SX/SC: Does not support M1353. When a Master PLC and a Slave PLC is connected, they are able to read/write maximum 16 WORD data. d) When the Master PLC is connected through COM2 (RS-485), baud rates and communication formats of all Slave PLCs must be the same (set in D1120).
When SA/SX/SC/EH2/SV/EH3/SV2 serves as Master, it e) When the Slave PLC is connected through COM2 (RS-232/RS-485/RS-422), baud rates and supports ASCII and RTU format. communication formats of all connected Slave PLCs must be the same as those in the Master PLC (set in D1120). When SA/SX/SC/EH2/SV/EH3/SV2 serves as Slave, it supports ASCII and RTU format. f) When the Slave PLC is connected through COM1 (RS-232), baud rates and communication formats of all connected Slave PLCs must be the same as those in the Master PLC (set in D1036). When SA/SX/SC/EH2/SV/EH3/SV2 serves as Slave, it supports ASCII and RTU format.
g) When the Slave PLC is connected through COM3 (RS-232/RS-485), baud rates and communication formats of all connected Slave PLCs must be the same as those in the Master PLC (set in D1109). When SA/SX/SC/EH/EH2/SV serves as Slave, it only supports ASCII format (Max. baud rate = 38,400bps). h) The start station No. (K1 ~ K214) of Slave ID1 is assigned by D1399 of Master PLC. Station No. of every Slave and Master PLC can not be the same (set in D1121). i) For one-to-one LINK: Connected through RS-232, RS-485, RS-422. PLC COM1, COM2, COM3 support many communication formats. j) For one-to-many LINK: Connected through RS-485. PLC COM1, COM2, COM3 support many communication formats. 8.
How to operate PLC LINK: a) Set up the baud rates and communication formats of Master PLC and all connected Slave PLCs and make them the same. COM1_RS-232: D1136; COM2_RS-232/RS-485/RS-422: D1120; COM3_RS-232/RS-485: D1109. b) Set up the station No. of Master PLC (in D1121) and assign the start station No. of Slave PLC from D1399 of Master PLC. Next, set up the station No. of Slave PLC. Station No. of Master and Slave cannot be the same. c) Set up the number of connected Slave stations and the number of data to be read in/written to Slave stations. For EH2/SV/EH3/SV2 (M1353 = On): Enable the function of the 32 conncected Slaves and reading/writing of more than 16 data (Max. 100 data).
Next, set up the No. of D registers for storing the read data (D1480 ~ D1495, D1576 ~ D1591) and written data (D1496 ~ D1511, D1592 ~ D1607) (See the explanations above on special D). SA/SX/SC only supports reading/writing of 16 data. d) Set up the length of data to be read from/written into the Slave. (If the user does not set up set them up, PLC will follow the initial setting or the setting set in the previous operation.) (See the explanations above on special D.) DVP-PLC Application Manual 2-131