SCO Unix Crontab Problems-Need Help

[ncra@ix.netcom.com (NCRA )]

I have a bourne shell that I need to execute in SCO unix 4.0 from a 
crontab.  The script is a communications upload using ecu.  The script 
runs just fine in terminal mode, but when it is executed in cron, it is 
not able to gain access of the modem for some reason.  

Q:  Is there something special that needs to be added to the crontab 
line in order to allow for tty access.  

Please let me know if you have any suggestions.