response from server to all clients in multiple client and single server model

Question

I have moxa E1212 product connected to a system and for communication I use modbus-tcp (jsmodbus package) and have multiple clients.
I need when a client sends a request to moxa (like turn on a LED), other clients be aware of that real time or server broadcast it's response to all clients.
How can I implement something like this.
currently I read status every 200 ms in a loop to notice if there is any changes:

    setInterval(function () {
        client.readCoils(start, count)
            .then(function (resp) {
                // console.log(resp)
                // socket.end()
            }).catch(function () {
            console.error(arguments)
            socket.end()
        })
    }, 200)

Answer 1

That broadcast does not exist in Modbus protocol, the only way for all clients to know about the coil state is to periodically read it, which seems to be what you are already doing.

The MQTT protocol would be better for what you intend to do, but it seems that this device does not support it.