Measurement Computing Personal488 rev.3.0 - Manual (Page 145)

Personal488 for Windows 95/98/Me/NT/2000 03/16/01 Troubleshooting C-7
Frequently Asked Personal488 Questions
Why does the driver return the error message “Time Out on Command?”
The most common cause for ‘Time Out on Command’ error is an improperly installed Personal488 interface.
Hardware conflicts, defective interfaces and miss-configured software all lend this type of time out errors.
In addition, failing to power your instruments or failing to connect the IEEE488 cable can also cause this error
What is the meaning of the following error message “Time Out On Data Read?”
The most common cause for this time out error is incorrectly configured EOS terminators. If Personal488 is
expecting a Line Feed (LF) when a Carriage Return (CR) is used, then the transmission will never terminate and a
time out error will occur. To correct this problem, review your instrument’s documentation to determine the
correct EOS terminator.
Another cause for this time out error is an incorrectly programmed instrument. If an instrument does not have data
to send or is not in the proper mode for transmitting data a time out error will occur. To correct this problem, refer
to the instrument’s documentation for the correct programming procedures.
What are IEEE488 terminators?
IEEE488 terminators, sometimes referred to as the EOS characters, are special characters used to signal the end of
a data transfer. Typical terminating characters are carriage return <CR> and line feed <LF> and problems will
occur when terminators are mismatched. For example, if Personal488 sends <CR><LF> when an instrument
expects <LF>, an error typically happens.
Why does my program run once then post the error message “Driver Not Loaded?”
This error message is typically encountered within the Visual Basic environment. Within a Visual Basic
application, all active device handles must be closed before the application exits and returns to the Visual Basic
environment. If any device handles are left, then upon restarting the program Driver488 will report “Driver Not
Loaded” indicating that the handle is unavailable. To recover from this error, exit and restart Visual Basic.
Restarting Visual Basic will force Driver488 to close all the handles and unload from memory. To avoid this error
use the Close function on all the open handles before stopping the application.
When running WinTest, why do I get the message “Driver Not Loaded ?”
The most common cause for this condition is an incorrect installation or incorrectly configured hardware. Refer to
the section “Driver and Support Software Installation” or “Installation Verification”