Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual Programming Concepts

2. Programming Concepts

accessible and the user can specify the starting register for storing the read/written data. For example, if the register for storing the read/written data on Slave ID1 is specified as D1480 = K500, D1496 = K800, access data length D1434 = K50, D1450 = K50, registers of Master PLC D500~D549 will store the data read from Slave ID1, and the data stored in D800~D849 will be written into Slave ID1.

f)Master PLC conducts reading before writing. Both reading and writing is executed according to the range specified by user.

g)Master PLC accesses slave PLCs in order, i.e. data access moves to next slave only when access on previous slave is completed.

9.Auto mode and Manual mode:

a)Auto mode (M1351): when M1351 = ON, Master PLC will access slave PLCs as the operation described above, and stop the polling till M1350 or M1351 is OFF.

b)Manual mode (M1352): When manual mode is selected, times of polling cycle in D1431 has to be set up. A full polling cycle refers to the completion of accessing all Slaves. When PLC LINK is enabled, D1432 starts to store the times of polling. When D1431 = D1432, PLC LINK stops and M1352 is reset. When M1352 is set ON again, PLC will start the polling according to times set in D1431 automatically.

c)Note:

„Auto mode M1351 and manual mode M1352 cannot be enabled at the same time. If M1351 is enabled after M1352 is ON, PLC LINK will stop and M1350 will be reset.

„Communication timeout setting can be modified by D1129 with available range 200 ≦ D1129 ≦ 3000. PLC will take the upper / lower bound value as the set value if the specified value is out of the available range. D1129 has to be set up before M1350 = ON.

„PLC LINK function is only valid when baud rate is higher than 1200 bps. When baud rate is less than 9600 bps, please set communication time-out to more than 1 second.

„The communication is invalid when data length to be accessed is set to 0.

„Access on 32-bit high speed counters (C200~C255) is not supported.

„Available range for D1399: 1 ~ 230. PLC will take the upper / lower bound value as the set value if the specified value exceeds the availanle range.

„D1399 has to be set up before enabling PLC LINK. Setting up this register during PLC LINK execution will not take effect.

„Advantage of using D1399 (Designating the ID of starting Slave):

In old version PLC LINK, PLC detects Slaves from ID1 to ID16. Therefore, when PLC LINK is applied in multi-layer networks, e.g. 3 layers of networks, the Slave ID of 2nd and 3rd layer will be repeated. When Slave ID is repeated, i.e. the same as Master ID, the Slave will be passed. In this case, only 15 Slaves can be connected in 3rd layer. To solve this problem, D1399 can be applied for increasing the connectable Slaves in multi- layer network structure.

2 - 7 9