The following application note is intended to aid a
first time user of the Serial icon in QuickLog or
WorkBench PC (DOS). In order for the Serial icon to
operate correctly there are certain software and hardware
guidelines that must be followed. Please check the
following list to ensure that you are properly set up to
use this icon:
- Check that the port is working correctly by
changing the mouse over to that COM port. Typing
mouse/n before loading WorkBench or QuickLog will
force the mouse to Com port n.
- Use "run" in the serial icon to test
your commands. It may be necessary to click on
"run" rapidly for a while to get the
command to engage.
- Having the mouse active on the screen can cause
problems. If the mouse is moving during data
acquisition it can interfere with the serial
communication and cause points to be missed.
Disable the mouse with Ctrl-Alt-8.
- Make sure that the correct modem cable is being
used. There are two types of end connection, DTE
and DCE. If both the computer and the external
serial device have the same connection a null
modem must be used. PC's are usually DTE.
- Continuous mode can lead to missed characters in
the input data. This is due to the one character
input buffer. If some characters have already
been sent when the serial icon accesses the line
then those characters are missed. This can be
overcome, to a degree, by using two input
commands, one after the other. In this way a
whole line of data is read, although the first
line is still lost.
- Make sure that the user knows that there is a
serial configuration in the menu that needs to be
set up to perform serial communication.
- The pause command waits for a specified time in
milliseconds. It is important to note that after
the pause is set the serial icon is exited and
the rest of the worksheet runs. Therefore, if a
serial icon is set to be accessed by WB once
every five seconds, and the pause is set to a few
milliseconds, the total pause will be 5 seconds
plus the pause time. To overcome this,
insert a five second pause into the serial
Before a user tries to get a complex set of commands
running they should first try to output or input
something simple. This will ensure that the serial setup
is correct and that all connections are made.