Registered: Sep 2000
Location:
Posts: 15

What exactly is the difference bewtween these two cables?

I seem to remember reading somewhere that one of them draws power from the Visor and the other draws power from the device it is connected to, but I can't remember which is which. What implications does each of the configurations have in terms of using serial devices like cell phones, GPS, switches/routers, and anything else you can think of?

Any other useful info about these cables would be appreciated.

Registered: Dec 1999
Location: Connecticut USA
Posts: 2682

The DataCord "modem' version (DCH-M9) from Mark/Space is Visor-powered while the "hotsync" version (DCH-H9) and the ATL cables are device-powered. Basically, this means that the DataCord "modem" version should work on most any device, while the "hotsync" and ATL cables need a device that provides power on the DTR(?) pin. I say most because there are no control lines on the DataCord or ATL cables, just TX and RX... if the device requires control signals, it probably will not work.

In my opinion, the ATL cable and DataCord "hotsync" cables are best suited as sync cables. The DataCord "modem" cable would appear to have the advantage for serial devices. For the record, I have an ATL cable and have used it succesfully to connect to an external modem but have not tried it with any other devices. I have not used a DataCord.

Read through the FAQ's about the DataCord for more specifics.

Also, the reason any of these cables require power at all is that the Visor docking connector serial signals are TTL and need to be converted to RS232 through the use of a transceiver circuit. There's an old thread that contains details about this circuit.

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Registered: Sep 2000
Location:
Posts: 15

Thanks MarkEagle,

I am aware of the TTL/RS232 signal problems.

I also read a post here somewhere that someone had successfully connected their cell phone to their Visor by simply connecting the appropriate RX, TX, and Ground pins on both devices together. The individual indicated that the cell phone had TTL voltage levels so no conversion was necessary. Do you know anything about this? I assume this depends on the cell phone model.