Help with transmitting Hex Values Over TCP

dalecooper1983 · 08-20-2011, 03:12 AM

Hi,

I am an AMX and Crestron programmer working within the AV industry for around 8 years. I have started to try using eclipse to write apps for android which will allow an android tablet to control AV equipment over a network. Here is a typical example.

NEC Projector NP3250 accepts commands on TCP Port 7142.

command to be sent to power projector on is $02 $00 $00 $00 $00 $02 $0D

(with hex being designated by $)

I am unsure about how to go about doing this any help would be greatly appreciated

sjums · 08-21-2011, 02:22 AM

I can't tell you exactly how to in Java, but I know that you'll use a socket object in C#.

Furthermore you'll probably have to convert those hex into bytes before sending them through the air

dalecooper1983 · 08-21-2011, 03:29 AM

Hi

Yeah already created a program using sockets which communicate over UDP to a different device but this uses ASCII Strings to communicate (converted to bytes).

I have tried a few different ways to send these values accross. I understand that they are values which could easily for instance 2 in decimal or $02 in hex or <STX> in ASCII i am just at a loss as to how to convert these into bytes which the projector will understand

Oh and I can see the activity lights flash on the Ethernet port on the projector when I send the command so i think the problem is to do with the way I am transmitting the command or converting it for transmission. I have also read about the flush command but am not sure if this is required. Sorry for my lack of understanding