Did you unplug the power to the directv receiver, then plug it back in?  

you also need to us a female to female null modem adapter in between the serial adapter, and serial-usb converter.  if you used a standard female to female gender changer, that won't work.

you don't need to add /r to the commands, it is done for you in the nevo serial setup of the directv device. 

Duh... I completely missed that the DirecTv requires a null modem adapter... guess that's on my shopping list as well. Did unplug the receiver as well as reset it, but of course nothing worked... no wonder, I don't have a null modem adapter...

The DVDO is killing me. That's not a null modem (as far as I can read in all the manuals), yet it doesn't respond to any commands.

I did a DVDO box not long ago in RS-232. Regardless, every manufacturer has their own approach and it takes a bit of time and study to get it right.

You know, one thought, it is not really necessary to kill yourself to use RS-232 codes. It is not significantly better than IR through the blaster or emitter, etc. and the IR codes are readily available for copying and pasting (on the DVDO web site).

That being said, if you really want to use RS-232 for all commands, here are my thoughts:

The settings below are consistent with the iScan VP30 software version v1.06 and later, per their RS-232 doc. Make sure your firmware is this rev. in the product. Could make a difference.

Input the correct baud rate and the other settings from the VP30 doc, into NSP3:
19200, 8, N, 1, None ( I don’t think you can select “Hardware” on NSP.) Then choose either ASCII or HEX.

I think it is just as easy to use HEX everywhere.

The say in this doc they have standard RS-232 wiring but they also call out pin 7 and pin 9 for flow control. But I think they say later they are not using them??? Try without pin 7 and 9 considerations and see if it works.

They also do not say specifically if a null modem environment is required. RE: Receive to transmit being switched. Since they don't say I have to assume straight through connections.

RE: The DVDO VP30 RS-232 .pdf document named (iScan VP-30 Automation Controls) =. Refer to section 4.1, Input Select:

They show you the code but you will notice (for Video 1) the first bytes are 4C which are in HEX (as labeled). When you start putting codes into NSP, you have to make a choice between Hex and ASCII. So, for example, the start bit in ASCII is STX. But then they supply you with Hex 4C for Input 1. You can’t mix the ASCII and Hex. So, notice they also give you the HEX equivalent of STX which is \x02

Also forget anything to do with replies, checksums and anything like that because NSP is not setup to receive acknowledgments, etc. unless you get very good with their Widget programming.

The tricky setting (I think) is Data Count. Referring to 3.1 Command Packet (Value = 0x30) you will see that DCNT1 and DCNT2 want to know how many characters you plan on sending. In example 3.1 for changing the brightness 21 to 1 they show the data count bytes to be 05. I believe they get this by counting the number of bytes after STX and before ETX. So, I think they get to 05 by counting the 30 (two bytes), HEX 21 for the “Brightness command) which is two bytes and the 1 for the setting you want, which is 1 byte. So added together, you are sending 05 bytes (maybe bits) resulting in 05 for DCNT1 and DCNT2.

So, the simple command “Input 1” should look like this: (In HEX)

\x0230054c\X03

\x02 is STX which must start every command.
30 is the requirement for sending a command. Always the same. Other # for queries, etc.
05 is the two bytes for length of command for DCNT1 and DCNT2.
4C is the Hex value for Input 1
\x03 is the end command telling the VP30 you are done sending a command.

Not positive this is 100% perfect but I think it should help you figure it out.

Happy New Year!

Dave
RemoteQuest.com

Here's how I programmed input 1 in Hex.

02 33 30 30 35 34 43 00 31 00 03

I'm going to try to use the code as you have it posted and see what happens... right now, nothing is happening, so it can only be better than what I've got. :-)

Really appreciate you taking the time and posting all this info!

No luck with either HEX (neither my own nor RemoteQuests code) or ASCII.. also tried with a null modem adapter, but that didn't work either. Either the wiring from the NC-50 serial module to the DVDO is not correct, or the RS232 input on the DVDO is not working properly. For now, I'm giving up on this and sticking with IR for the DVDO... everything else seems to work fine. I'll post my files later on.

Well, when I get in these odd rs-232 situations, if I really had to make it work on RS-232 and the "created-codes" don't work, I have plugged the device directly into a PC and used a "Terminal" program to send the "created-codes" to the device. The good part is the DVDO will send back info which can assist in determining what might be wrong with the code.

I see you are trying IR and sometimes that is just better all the way around, especially when you cannot make it work on rs-232.

Dave
RemoteQuest.com

I agree, Dave...that's a great way to troubleshoot. Especially if the issue might have to do with command formatting, trying variations in the Nevo itself is pretty slow and tedious. But with a terminal program, you can quickly try different options and get immediate feedback, including a running record of the session.

Yup. At least you get some feedback. I reviewed the DVDO RS-232 doc in detail and it is not particularly clear.