ISaGRAF PAC supports Modbus Master function to connect other Modbus Slave devices to read or write data. For example, ICP DAS provides many easy-to-used Modbus blocks to read or write the values of Word (16-bit signed), Real (32-bit floating point), Long Integer (32-bit long), Boolean (Bit), etc. But, when using many Modbus function blocks in a PAC (for instance, using 50 or may be 100 to 2000 Modbus blocks), the ISaGRAF projects become huge. This makes the program complicated and difficult to maintain.
The new Modbus function blocks, Mbus_AR and Mbus_AW, can input variable parameter values. If apply them in a “For” loop, the program can become much smaller and easy to maintain. The other advantage is the Mbus_AR and Mbus_AW blocks consume less CPU execution time. |