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Serial data device needed

T

Thomas Abell

Jan 1, 1970
0
I am searching for a circuit diagram for a device that I can build. I need
this device to divide serial data while amplifying the signal so that both
outputs are equal to the input.

I need this because I have a serial device that is providing a one-way data
flow into the serial port on my computer. I want to be able to split this
signal and put it into two ports. Simply running the data in parallel to
both com ports doesn't work because I believe that too much signal is being
lost.

Can anyone offer suggestions?

Thanks.
 
B

Bill Jeffrey

Jan 1, 1970
0
Is the data at TTL levels? Is so, get a hex inverter IC (7404 seies,
IIRC). Put the input stream into one inverter, connect its output to
the inputs of two other inverters. The outputs of those inverters are
what you want. Since there are six inverters in the package, and you
just used three of them, you can buffer two data lines per package.

Bill
 
B

Bill Jeffrey

Jan 1, 1970
0
Sorry for the earlier post. The serial port is RS-232, which is not
directly TTL-compatible. Though there are several versions of RS-232, I
believe the common one uses +12VDC and -12VDC to represent the two logic
states. To buffer this, you will need a +/- 12VDC supply, and a couple
transistors and a couple resistors for each of the lines to be buffered.
Same principle as the inverter IC, but implemented with discrete
transistors.

Bill
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F

Franc Zabkar

Jan 1, 1970
0
I am searching for a circuit diagram for a device that I can build. I need
this device to divide serial data while amplifying the signal so that both
outputs are equal to the input.

I need this because I have a serial device that is providing a one-way data
flow into the serial port on my computer. I want to be able to split this
signal and put it into two ports. Simply running the data in parallel to
both com ports doesn't work because I believe that too much signal is being
lost.

Can anyone offer suggestions?

Thanks.

You *should* be able to drive two RS232 inputs from one output. If
not, then you could buffer the output with an MC1489 quad line
receiver and use this to drive an MC1488 quad line driver.
Alternatively, to avoid the need for additional +/-12V supplies, you
could use a single +5V Maxim IC with on-chip charge pumps.


- Franc Zabkar
 
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