Chapter 5 Monitoring Function; Automatic Address Detection - Mitsubishi Electric MELSEC-Q Series User Manual

CHAPTER 5
The AnyWire DB A20 slave module has the specific ID (address). When the master module sends the ID (address),
disconnection and existence of slave modules are detected by receiving a reply from the slave module having the
corresponding ID (address).
The master module uses the automatic address detection function to store the addresses of the currently connected
slave modules in the EEPROM.
This information is stored even when the power is turned off.
Then, the master module sends the registered addresses in order. If the corresponding slave module does not reply,
the ALM LED indicates that a disconnection has occurred. Then an error flag is returned to the memory area on the
host side.
Furthermore, this slave module address can be checked.
5.1

Automatic Address Detection

Automatic address detection is a function to store the ID (address) of the connected slave module in the EEPROM of
the master module.
In the initial system startup, the ID is not yet registered in the module. Therefore, when the power is on, the "ALM" LED
and the "D/G line disconnection" flag are turned on. ( Page 41, CHAPTER 4, Page 50, CHAPTER 6)
I/O data can be transmitted in this state. However, to use the disconnected branch line detection function, execute the
automatic address detection function at this point.
Execute the automatic address detection function in the following cases.
• When starting the system operation after confirming that all the slave modules connected to the master
modules are operating normally
• When adding a slave module after starting the system operation
• When removing a slave module after starting the system operation
• When changing the address of a slave module after starting the system operation
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MONITORING FUNCTION