Connecting Car Dock Serial to PC

I bought a gender converter (male to male) so I could connect the cable which came with the empeg to the serial cable on the car dock.

The problem is when I do this; nothing is seen on the com port. If I connect the car dock serial cable directly to my com port I see output.

What am I doing wrong? Can I not use the cable which came with the unit? Do I need a straight through cable?

Thanks

The 'serial cable' that comes with the unit and which is used for kernel and software upgrades, is as you have discovered, a cross-over cable [i.e. a DTE to DTE cable also commonly called a 'null modem' cable].

The output pins of the serial connector on the docking sled are not crossed over (and this connector appears to be a DCE device).

This means you can plug the docking sled cable straight into the PC serial port as its a DCE device connecting to the PC serial port (a DTE device) so no cross over cable is needed (as you've found).

So, what you need is a straight through 'extension' cable (also called a DTE to DCE straight through cable) with a 9 pin male on the Docking sled end and a 9 pin female on the PC end.

However you should also note that one of the pins on the Docking sled connector outputs +12 Volts [this is Pin 9 I think], which may be confusing (but should not be harmful) for your PC, as pin 9 is normally incoming Ring Detect and that toggles up and down to inform the PC that you have a incoming call.
If you find that your PC (or more likely, the software you use to communicate with the unit) doesn't like the straight through cable then this may be the reason and you may wish to buy or make up a bare bones straight through cable that connects only pins 2, 3 & 5 to remove the 12 volts pin from the interface that the PC sees.

Also note that according to Altman [Hugo] docking sleds for units earlier than about serial#1050 had a wiring problem in that earth wire (pin 5) of the serial connector on the docking sled was not wired up/was missing - there is a comment about this on the BBS elsewhere and possibly in the FAQ and a workaround.

If you Empeg/RioCar's serial number is higher than about #1050 then this won't be a problem.

So if I use a straight through cable will I be able to do updates?

I already have a barrel connector rigged up to trick the player into home mode to make updates possible.

Yes, with such a cable in place you should able to, provided you, as you say, "install the Barrel connector" to trick the player to think its NOT in the car.

Well I finally got my box built! It's sweet anyway. I now have a hum when the serial cable is connected.

My computer and empeg are connected to my stereo @ the same time (different inputs of course). As soon as the serial cable is removed the hum goes away

Mark if your reading this, I remember seeing a ground cable on your cage, what was it for?

Any ideas how to get rid of this hum?

Early docking sleds [earlier than about serial number 1050] had no earth wire on the serial cable that connected to the docking sled.

One fix [and probably the easiest] is to make up a serial male/female DB9 connector pair that plugs onto the end of the docking sled serial connector and puts all the 9 pins straight through and also connects pin 5 to the metal chassis of the docking sled.

That may make your hum go away as it sounds like you have a earth loop between your PC? and your Empeg.

Of course, your sled may not have the missing ground wire problem, in which case, it could be a earth loop caused by having the grounds connected between your docking sled and the PC - in which case try plugging the PC into the same electrical outlet that the Empeg power supply is plugged into [this should help eliminate the ground loop problem I think].

PIctures. We want Pictures! (Well I do anyway)

Bruno

Thanks number6, my serial # is up in the 4000 range. Unless I have an old dock. Since I can now install a new HiJack version via Ethernet, I've just disconnected the serial cable until I need it

Bruno I'll post pictures when I get a hold of a digital camera. It's basically a nice small plastic box (quite good quality, I bought it at a store near Active Surplus). I might have to add a fan because the empeg with the docking cage was a tight fit.