通过tcp向enfora trakers OTA发送命令

I work for a company that provide service to track vehicles with gps devices, rigth now I need to find a way to send commands to an enfora devices over the air using the tcp protocol, I have tried many ways with no results unfortunately. I just can send commands via sms.

I would like to send commands to request the current position, to open doors, etc.

This is the code I use to sent AT commands to other brands and it works like a charm!

var toBeSend = Encoding.ASCII.GetBytes(msj);
tcpClient.Client.Send(toBeSend);

What can be the problem, anyone knows?

If anyone have a script no matter if it is in c#, Java, PHP, Python, etc. please share it with me.

Using Netty I do this:

channel.write(ChannelBuffers.copiedBuffer(message, StandardCharsets.US_ASCII));

You have to consider that to send an AT command via TCP you have to add a header to the message and also the checksum.