ActiveX Control Guidelines
The Open function can fail on
another device is setup to use the port that is trying to be opened.
other drivers/devices from the port you are trying to open, including
drivers and network re-directs.
When reading a parallel port's
the I/O ActiveX control will use the RS1284 protocol to read the data
The recommended serial cable
is a "Null
You can connect two PCs together with
cable and send data to/from the connected PCs. Connect the PCs and run
the IODemo on both PCs and select the correct ports and do
and writes. You can run a terminal program on one PC in place of the
How often status is monitored before
is fired is controlled by the property StatusEventInterval.
The default value is 250 milliseconds. Making this value smaller makes
status events more sensitive to a change. A value of 0 disables the
ParallelStatus can fail on Win
there is a printer driver setup to use the parallel port that I/O is
done on. Remove other drivers/devices from the port you are trying to
including printer drivers.
For a more responsive user interface
I/O, consider using the Background mode of operation. Set the
property to MODE_ASYNC (2).
During application shutdown
can occur. To address this issue, ensure no calls to the I/O object are
made after the I/O object is destroyed. To do this, move the I/O object
shutdown processing to be done before the application shutdown
is done. Note: It is recommended that "IO.Close()" is called before an
application begins to shut down.
To clear the input and
Call the "IO.Close()" function and then reopen the port via the
Events are fired from the primary
If an event does not fire, call the IO.Wait() function with a
of 100 to 1000.
On Win NT, the parallel port does may
accept timeouts. To avoid a dead lock, check the port status
before doing I/O on a parallel port on Win NT.
Note: On PC's setup for
as Chinese, Japanese, or other symbol type languages, you may have to
the ReadBytes() and WriteBytes() functions to avoid unwanted Unicode
Using the purchased copy:
You should ensure that only
copy of the "IO.OCX" is on your development machine. You may have to
the I/O Control onto the form you are using it with. Then re-compile
NOTE: if you test deploy your
on your development machine, you may end up with more than one copy of
"IO.OCX" on your machine. Delete the "IO.OCX" files and re-install the
I/O Control for further development.
Redistribution of files:
1) You will need to redistribute
with the application that you write.
2) "IO.OCX" may need to be registered
the OS when it is distributed.
a) If you distribute with
Express 2" the IO.OCX will self register.
b) If you distribute with Visual
utility the IO.OCX will self register.
c) Other method: run "Regsvr32.exe
Files you may need to
Note1: IO.OCX is dependent on
MSVCRT.DLL, OLEPRO32.DLL, and
OLEAUT32.DLL. You will need
to install these files in the Windows
Note2: IOOCX.SYS is
the Windows system /drivers directory on NT based OSes (NT4.0, Win2000,
WinXP). And you will need to integrate IOOCX.REG into the system
Note3: IOOCX.SYS is not
Note4: On Win95 you may need
install the following:
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