CS3000: multiple PLCs connected to one ALR121

When using Modbus communication, be sure to distinguish the device addresses of the PLCs

This post was last edited by fengzaiqingdao on 2015-9-28 21:45. First, define several physical addresses for different PLCs; one PLC corresponds to one physical address. For example, PLC_1 corresponds to A40001, with a length of 4； The physical address corresponding to PLC_2 is A40005, with a length of 4 (note that the length must be even). Second, assuming PLC_1 starts at %ww001, then the address range corresponding to PLC_1 is %ww0001~%ww0004 ； Therefore, the address range corresponding to PLC_2 is %ww0005~%ww0008. Assuming that the address range %ww0002 of PLC_1 is defined as digital signals (this can be customized), the corresponding digital signal addresses will be %wb000201~%wb000216 ； Assume that the %ww0007 address range defined for PLC_2 is set as digital signals (this can be customized); the corresponding digital signal addresses will then be %wb000701~%wb000716. Thirdly, define the digital signal tag numbers for the respective bit addresses: click on %WB tag number definition call in the dropdown menu under Tools, enter the corresponding bit addresses in the appropriate field, and fill in the tag name with the instrument’s tag number. Fourthly, it should be noted that no instrument tag number is reused within the configuration; if such reuse occurs, an error will be generated during compilation. The bit addresses of different PLCs are unique, so no special distinction is needed – in other words, every bit address is unique and does not require differentiation