IRTrans Support Forum

thanks - this looks ok.
I suppose you did set the correct parameters for the connection? 9600Baud, no parity, 1 Stopbit?
Also check the RS232 cable connection: left jack (next to power connector), firmly in

Thanks. I've configured the connection parameters accordingly and I'm using the correct output port.
I'll check it again tonight (perhaps it wasn't pressed in firmly enough? )

When sending the command, I select "all leds". Is that also correct?

That sounds good.

nope: no luck

rs232 configuration set via webinterface: 9600/n/8/1 Transmit RS232 via UDP = on Recv. RS232 relay via UDP=on
screwed open the rs232 plug: all (3) wires correctly placed and firmly in place
turned on the denon first, plug rs232 in the denon, afterwards in the irtrans
connector in port next to the power plug: pressed in firmly

learn new rs232 command: MUON\r (mute on) in a new remote
send the command: nothing happens
send an ir command to the samsung tv using the same interface: works (so the interface and module works)

It's driving me nuts: why isn't it working?!
(and I really appreciate your efforts so far...)

hmm, strange.

Is there anything in the settings of the Denon receiver to activate/deactivate RS232 inputs?

To check if there is anything on the RS232 connection:
Plug a null modem cable between the IRTrans RS232 and your computer (2 female connectors, pin 2 of the first has to be connected to pin 3 of the second and vice versa, pin 5 to pin 5 - only pins 2,3 and 5 are needed), open a terminal such as hyperterminal to listen on the computers com port and send data via the IRTrans. If you "see" what you have sent the IRTrans is working correctly and there is an issue with the Denon...

the rs232 on the denon can't be switched on or off: there are no configuration options on the denon for the rs232 port.

I have three macs and 1 very small pc, all without a COM-port
Perhaps I can test the cable with a multimeter to check if there are voltage changes when sending a command?

or another thought: perhaps the denon expects the ground on pin 5 in stead of pin 1?

You will need an oscilloscope to measure the signals. Changes occur at a few kHz, a multimeter is too slow to pick that up.
Even then - analysis of the signal is pretty difficult, you would notice changes in voltage but confirming that the correct bits are transmitted is a whole different story.

Is there a possibility to use a different computer for testing? maybe at/with a friend or so?

normally the signal reference is connected to pin 5, pin 1 is for cable shielding. normally they should be left separated.

mmm... no friends of mine have the same geeky interests as I do

I won't argue on the pin assignments, but I'm triggered by this post:
http://denon.custhelp.com/app/answers/detail/a_id/82/~/rs-232-compatibility-%26-pin-configuration

Perhaps it does expect some sort of Common Ground?!
(and if so: will any type of ground do?)

reviewing the denon information i'd say: Give it a shot.

The RS232 stardard defines: pin1 - common ground and pin5 - ground (signal ground)
It sounds like this has been switched.