I-7000 Remote I/O 013

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Q.How can the 7000 modules identify the correct command ?

Ans: Every 7000 module has it’s own module address. The command string always include the desired module’s address. When the host computer send the command string, all the 7000 modules in the RS-485 network will receive this command string at the same time. Then All the 7000 modules will interpret this command string simultaneously. They will fetch the address field and identify the destination address. Only the module with the same address as the destination address will response to the host computer. All the other module in the network will bypass this command string and waiting for the next command.

For example, $012[0x0D] is a validate command string and the destination address is 01. The 7000 module with address 01 will response to this command.

Written by David Chen 

Date:2002/12/24