Using Scream!
5.1.9 Ports
The
Baud Rates
pane of the
Configuration setup
window allows you to program the
baud rate and stop bits for the DM24's output port.
The baud rate you choose must satisfy two conditions:
•
It must be high enough to allow all the transmission of all data generated by
the digitiser at the sampling rates you have chosen. For three streams of data
at 100 Hz, for example, 9600 baud will usually be sufficient. If you wish to
transmit 200 Hz data, however, the baud rate must be at least 19200.
•
It must be low enough to fit within the bandwidth of the communications
infrastructure you are using. While modern modems often offer transfer rates
up to 56k baud, the telephone or transmission lines may not support these
rates. The same holds true for radio communication links.
Usually, the transmit and receive rates of the data port will be the same. If not, you
may select different data rates by removing the check in the box marked
Identical
TX/RX rates
.
The
Stop Bits
option allows you to choose whether the serial link uses 1 or 2 stop
bits. In most cases this can be left at 1, although 2 may be required if you are sending
data over ‘difficult’ transmission lines (for example, some types of radio link). Using
2 stop bits will add a 10% overhead to the data.
You will also need to set the data rate for Scream!'s local serial port, as well as for the
EAM or other communications device (if you are using one). In Scream!, you can
configure a serial port by right-clicking on its icon (
not
that of the digitiser) and
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Issue U - December, 2021
