I have a Samsung UN60EH6000 LED TV that I have connected to my PC via the EX-Link port with a 3.5mm to USB serial cable (found here). 

The TV will not respond to any commands I send it.  I can successfully open a port and send commands, but I can never see a response.  I am using RealTerm to send commands.  I've also used Hercules and PowerShell to open a port and send commands.  I've tested with various commands, but I'll use the power off as an example. 

In RealTerm, I am sending this:  0x08,0x022,0x00,0x00,0x00,0x01,0xD5 as Hex.  When I look at the Log file, I see that the WriteCom is sending [08]""[00][00][00][01][D5].  I'm not sure if this is due to RealTerm, because sending data through a byte array in PowerShell did not work either. 

I am using BAUD 9600, Parity None, 1 stop bit, and Data bit 8.  I'm not sure if I have to set up the Samsung to receive commands.  Some sources said there was a RS232 option in the service menu, but I didn't find any such option.  Maybe the name changed? 

Any information would be greatly appreciated!