Dear Forum,

Would you be so kind and advise me on the following....

I want to make a voltage logger and to remotely control it (turn on/off, read / download voltage readings)...

The data logger will be placed in a non safe (for human occupancy) place and remote access might be needed...
The cable pulling is not the best option (otherwise the ordinary multimeter with logging function will do).... therefore i thing i would need a GSM / cellular network module... control the data logger and view / download readings...

Thank you so much...

 

Welcome to AAC.

I suggest you look at the offerings from Particle. They offer a complete solution (hardware + airtime) for IoT, which includes remotes sensors. It is a development board or module which uniquely includes a base level of airtime, free, for the life of the device.

It may well be enough data that you don't need to pay for any airtime, but if not, it's not very expensive. The service includes a dashboard for fleet management, and OTA (Over The Air) updates for your program.

Alternatively, Blynk offers a similar service though not identical, so you should explore each.

 

If you want to build something, I suggest starting with an ESP8266 or similar breakout board. These modules are cheap, have WiFi, use the Arduino IDE and there is a lot of code available on the Internet from the Arduino community.

 

This one has 0 to 4.5 volt serial (TTL compatible) compatible with RS-232 level shifting if needed. You can run a very long 3 or 4 wire cable to it but it should also be easy to interface to a RF link that used TTL serial of RS-232 signaling for the physical layer.
http://www.cappels.org/dproj/VR/AVR_Data_Logger_and_Voltage_Recorder.html