Hi everyone,
I’m trying to upgrade some commun “dumb” wall switch that we can find on any hardware store with the help of some microcontroller.
I’m trying to find the best topology / protocole to use so the wall switch can communicate with the breaker box or some centralized logic that will operate actuators.
until now I was using TCP/IP based protocole (like mqtt) to achieve automation, but deploying cat5 / hub based topology is a real pain.
so I was considering using bus instead.
when I was searching for some RS485 based protocole, Modbus showed up several times and I started to look into it.
the Slave / Master topology seems to be really suited to drive actuator (like valve, motor, relay) but what if a slave is actually a sensor that will report events (like button presses)
has I understood slave devices cannot talk to master without the master initiated the communication first.
so how can ModBus switch can report events?
Is the master polling each slave to see if there was a button press?
Thanks for your help
I’m trying to upgrade some commun “dumb” wall switch that we can find on any hardware store with the help of some microcontroller.
I’m trying to find the best topology / protocole to use so the wall switch can communicate with the breaker box or some centralized logic that will operate actuators.
until now I was using TCP/IP based protocole (like mqtt) to achieve automation, but deploying cat5 / hub based topology is a real pain.
so I was considering using bus instead.
when I was searching for some RS485 based protocole, Modbus showed up several times and I started to look into it.
the Slave / Master topology seems to be really suited to drive actuator (like valve, motor, relay) but what if a slave is actually a sensor that will report events (like button presses)
has I understood slave devices cannot talk to master without the master initiated the communication first.
so how can ModBus switch can report events?
Is the master polling each slave to see if there was a button press?
Thanks for your help