is Tcp-Modbus basically a Cleint-Server socket communication? - tcp

I'm building a TCP-Modbus application on PIC32MZ starter kit and My kit should act as Modbus-Slave device (read some data available on the ADC channels and send it to Modbus Master on every poll it will make), but I'm not sure, whether my device will be in TCP-Client (device will going to connect to a server) or TCP-Server (server will connect to my device) mode?
Regards,
Aatif Shaikh

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Re-enable Bluez advertising after connection, through d-bus interface

I have a BLE Gatt server, which is setup using the d-bus bluez interface (version 5.54).
Advertising is working using org.bluez.LEAdvertisingManager1 and can be viewed using a BLE scanner Android app.
Making a connection to the server stops the device from advertising, and it is no longer visible on a BLE scanner.
Disconnecting doesn't start advertising again.
I've seen the same issue described here, with a solution using hcitool commands.
Is there a way to re-enable advertising using the d-bus interface only?

Raspberry Pi3 BLE only accepts a single connection

I have created a BLE peripheral that exposes a GATT service. It uses BlueZ 5.50, but it seems that only one device can connect to the GATT service. When the device is connected, then other devices can't see it anymore. It's not showing up in a scan anymore and if it was already scanned, then I can't connect to it anymore.
It seems to be a limitation or configuration issue in BlueZ, because when using the Paypal GATT library it can handle multiple connections. As far as I know, the RPi3 BLE chip should be able to handle up to 10 connections.
Does anyone know if this can be done using BlueZ?
The Paypal GATT library directly connects to the HCI device and bypasses most of the kernel stuff. BlueZ depends on kernel drivers and user-space applications and is capable if the driver reports that the controller allows multiple connections. You need a decent BLE controller and a recent kernel to make it work.
More information can be found in https://github.com/bluez/bluez/issues/12.

computer AND esp8266 WITH arduino

how the bellow connection can be done , what the protocol that must be used to send bytes from computer through it's serial WiFi and receive the bytes in Arduino using ESP8266-01 WiFi Serial Transceiver Module.
computer AND esp8266 WITH arduino
It depends on what you want to accomplish, and what roles you want the computer and the arduino/esp combi to play. You can put the ESP in station or access point mode (or mixed), and have it talk to the arduino via the serial interface. The communication with the PC will indeed go via wifi/tcp protocol, but depending on your specific requirements you will have to decide one the roles. Then you can make the ESP a web client or a web server, mainly depending on the direction of the flow of information.
I assume you want to query the Arduino from the PC, in which you can send a HTTP/GET request from the PC to a simple web server on the ESP.
There are various examples in the Arduino examples that do just that to give you a start, available when you install the ESP library in the Arduino IDE, see: https://github.com/esp8266/Arduino
HTH

Can we use asp.net SignalR for controlling remote connected devices from some central server?

Can we use asp.net SignalR for controlling remote connected devices (not a computer or mobile just a different electronic device having its uniuque mac address) from control server? Server will decide when an alarm is supposed to ring from the device and if user not responded to the alarm then the device should send back some kind of signal or message to central server that alarm was not responded.
Yes , for this you will have to use a some sort signalr client
http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-net-client
http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-javascript-client
so what ever operating system you install on the device it should support .net or java

manage of two different socket

I have a server program developed in Qt
A computer can connect to the server with a Qt Application
A mobile phone (android programmed in Java) that can also connect to the server Qt
The management of data reception and transmission differs.
I want to know how to recognize the socket of the computer and the phone.
Thank you

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