Controlling VM201 via TCP

Modules VM201
1

Hallo,
I’m trying to write a Java application which turns ON/OFF the relays of a VM201. I found this thread which explains some commands for communicating with the VM201:
viewtopic.php?f=37&t=8598&p=33039&hilit=VM201+protocol#p33039

So i tried having my Java application opening a TCP connection to the VM201 and sending the string

0206$4F01A803

to turn the relay channel 1 ON, but this did not work. The relay did not react.
I am however able to access the VM201 with a web browser and turn relays ON/OFF with that interface. Could you fellows give me some advice on what I’m doing wrong?

2

It could have a few hundred causes since we know absolutely nothing about your application.

[quote]So i tried having my Java application opening a TCP connection to the VM201 and sending the string[/quote]The word “string” worries me though, because two ascii characters, for example “02” are not the same as the single hexadecimal number 02h.

3

Yes, I did try to send a String. I will try to send a bytearray with the hexadecimal numbers and see if I am more successful with that.

4

That sounds perfect