Rs232

audiobliss

Ok, so now that I have my nice new (almost...it looks it!!) CDR-HD1300, and I've hooked up 18' of composite video cable so I can view the info on my computer monitor, I need to get this RS232 thing straightened out. I ripped one CD and entered the album/track title using the remote...I'm not doing that again, lol.

I'm a bit confused about the RS232 port and how it connects to a computer. Does it just connect to the computer's serial port? I've read that RS232 ports use a null modem cable, which has two pins switched over, and then I've read that you can use a regular serial cable, too. (None of those comments have been specific to the CDR-HD1300...just various things I've come across in my searches today.) What's the deal? Does it have to be a null modem cable? How hard are they to come across, and how expensive are they? I've seen a few good deals for them online, but my online transactions are restricted to CP, so unless you have one laying around (seriously, lemme know if you do!), I'm left to buying one at a brick & mortar joint.

Also, is there a length restriction to these? I really really would like to hook it up to my desktop, which would require 18' - 20'. However, if that's not possible or is cost-prohibitive, I *could* settle to always using my laptop.

So, fill me in here.

Thanks!!
audiobliss

TheReaper

Your 20' length should not be a problem (I don't know the limit, but I have done 25 ft).

EDIT: Your cable will also have to match the connectors Male->Female, 9pin/25pin.

It has been a long time since I have made a serial connection, but here is what I remember:

There are 2 types of connectors:

DTE - data terminal equipment (computer/terminal)
DCE - data communications equipment (modem)

If you are hooking a computer to a modem (DTE -> DCE), you use a straight-through cable.

If you are hooking a computer to a computer (DTE -> DTE), you use a null-modem (cross-over) cable.

The reason being, rs232 uses unidirectional signals, so the transmit-pin has to connect to receive-pin on the other end.

You really have to read the manual on your CDR to find out what it is. Or if radio shack still sells them, 20+ years ago I bought an rs232 tester (little inline connector with leds that light up red/green for signal).

If your CDR only has a pinout diagram, do a search on the internet for the standard DTE/DCE pinouts to match them up.

The signals are connected as follows:

DTE <-> DTE
==========

SG <-> SG signal ground

TxD -> RxD transmit data
RxD <- TxD receive data

RTS -> CTS request to send
CTS <- RTS clear to send

Rare, but sometimes:

DSR <- DTR data set ready
DTR -> DSR data terminal ready

I never used the other pins.

TheReaper

Here is a link to how someone else did the connection:

http://www.audioasylum.com/audio/digital/messages/64648.html

...A quick visit to the Yamaha website and download later, and I had the Yamaha album/track title editor software on my PC. Needing a cable to connect the PC to the Yamaha, I consulted the manual, the Yamaha and various other sources, but could not find the specifications for the RS232 connection (ie pin allocations). I eventually contacted the Yamaha distributor and received a fax containg the pin allocations. I then visited a local PC cable specialist and established that the required cable was a female-to-female, 9-pin to 9-pin "Null Modem Cable" and bought one.

audiobliss

TheReaper - thanks for all the info very much! And that post on audioasylum is invaluable! That pretty much answers my question and several others I hadn't asked yet all at once. Thanks very much!

audiobliss

Ok, I think I've found a solution here, browsing through the cables Tiger Direct offers. I found a 15' DB9 to DB9 Null Modem Cable that's female-to-female, which is what I'd need (right?). However, since it's too short, I can just add an extension. And for an extension, I found a male to female cable I think will work. I'd want it to be a regular serial cable, 'cause if it were also a a Null Modem Cable, then the crossed over wires would then be cancelled out (or become 'null' ).

So, tell, me, does that make sense? Think it'd work? Here are the two cables:

The 15' F/F Null Modem Cable
6' M/F serial cable

Tell me what you think! I have a friend who I think buys from Tiger Direct and so would be willing to order it for me.

TheReaper

You have it correct (a null modem cable, extended with a straight through cable).

I have no idea about the quality of those cables, but I see no reason they wouldn't work. I have used worse, a 25' 6-wire phone cable with cheap-**** rat-shack connectors on the ends, then a 3' ribbon cable with clip on connectors for the crossover (hand split and crossed), and it worked.

audiobliss

Awesome. I won't see my friend until Friday, but when I do, I'll see if he'd be willing to order these cables for me.

Thanks for your input! I think I've got this squared away now, assuming I can get my hands on the cables (and patiently wait for them to get here)! Appreciate it!

Michael