Re: Ability to drive multiple IR transmitters independantly from PC

[nobody@xxxxxxxxxxxx (Dave Houston)]

Alexis <snoopy@xxxxxxxxxxxxxxxxxxxxx> wrote:

>Dave Houston wrote:
>> What's the distance from PC to displays?
>
>Ranging from about 5 metres to about 20 metres - I had planned to either
>use USB repeaters or IR LEDs on a long bit of wire, either of which
>should be adequate workarounds for the distance, I hope.

USB repeaters are costly compared to long IRED leads.

>> I would ask the designer of USB-UIRT if you can use multiples. If so there
>> is an API for these devices and they are reasonably priced.
>
>My concern with this solution is that it will probably work for a small
>number of devices, but I have concerns as to whether it will work with
>the full complement of 20 devices.  I am unsure as to how the USB UIRT
>device interfaces with the PC.  If it acts as a virtual serial port, I
>suspect this may be an issue, as Windows will, as far as I know, only
>support a maximum of 16 COM ports active at any time.  (For the record,
>using Linux is sadly not an option in this case).

Windows supports 256 COM ports so this should not be a problem. However,
although they use FTDI USB-serial chips, I don't think USB-UIRT uses virtual
serial ports. That's why I suggested you contact them to be sure they can
distinguish between 20 devices. I believe FTDI provides for this by giving
you a way to assign an ID to each device but its been too long since I
looked at the details. (These days, a few hours is too long.:()



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