I have a preamp/processor (Krell HTS 7.1) with an RS232 external control communication port. I also have an Escient DVDM-300 media manger connected to a couple of Sony DVP-CX777ES changers. The Escient media manager is connected to my home network and has a cool web interface (Fireball-PC), which I can use to control the media manager and the changer functions through PC’s connected to my network.
When I listen to music outside on the deck, I take my wireless laptop and I am able to select the music that I want to listen to and control the changers. My deck speakers are a separate zone and connected to a 2-channel amp that is connected to Zone 2 out of the pre/pro.
So the Fireball is on the network and you can communicate with it via a web interface from any PC connected to the network, but how are the changers connected to the Fireball? Does the Fireball also have RS232 outputs and that is how it is connected to the cd changers?
If so (or even if it is connected via some other means like USB, Firewire, null modem cable, etc) what the Fireball does is take the data sent over the network (it is acting as a 'server') and transcodes it to the specific command that the connected devices needs to see. So if for example, you click on a button that says 'next track', the Fireball sees the 'next track' command, determines that the connected device uses 100 to mean 'next track', and sends 100 over the RS232 to the changer. [Remote control commands are nothing but numbers].
Problem:
I can’t control the volume.
The Fireball-PC web interface software has provisions for volume control through an external control device. The software communicates over the home network to a TCP/IP network device and you can configure the volume up/down/mute buttons with the RS232 command specific to the device you are trying to control.
Has anyone used a 10/100 mbps UTP Ethernet to serial RS232 server as the external control?
Essentially this is a device that has a DB-9 RS232 connector (connect to pre/pro RS232 com port) and an RJ-45 connector to plug in to the LAN wireless router.
There is no such thing that I know of and probably for a good reason: how would it work? RS232 is an extremely low level serial communication protocol and the device would have to know what the payload of the IP packets contain, extract that data, and form a new stream to send out over the RS232 port (just like the Fireball itself does for the CD changers).
Is there more than one RS232 output on the Fireball so you could connect the pre/pro in addition to the changers? That should work as long as you can tell the Fireball what command to send to the pre/pro when you send the volume up/down/mute from the web interface.
If you can elaborate a bit on how everything is currently connected, we could probably come up with a workaround but it will be a hack no matter what.
Of course the simple solution is to just get an RF remote and program it with the Fireball's commands and the volume/mute functions of the pre/pro and not use the web interface.