Installation guide

4-5
Programming Problems
f Why are the Win32 COMM API functions returning fail codes?
Why are the PComm Pro library functions returning the fail code
“SIO_WIN32 FAIL”?
The fail code for COMM API functions has a different meaning from the
fail code for standard COM drivers. You may receive the fail code when the
network connected to the NPort Server Lite is unreachable, or if the NPort
Server Lite is offline. If the network connection is through the Internet, the
network could be unreachable during heavy Internet traffic. This does not
mean that the NPort Server Lite has failed. To recover from this type of
error, you can modify your program so that the port is automatically closed
and then re-opened.
Try the following steps to resolve the issue:
1. Re-open the port if the fail code is returned during the open (i.e.,
sio_open) session.
2. If the fail code returns while writing data, reading data, changing
settings, etc., close the file handler and then try to reopen the port.
3. If the device server is off-line, turn it on and plug it into the network.
4. Verify that the route to NPort Server Lite is reachable by typing
Ping [NPort-Server-Lite-IP-address]
If a route to the NPort Server Lite cannot be established, check your
host’s routing table and the NPort Server Lite’s routing table.