Siemens SIMATIC TIWAY 1 - Manual (Page 155)

HOST COMMAND SET REFERENCE
UNILINK HOST ADAPTER 5–70
USER MANUAL
5.7.3 Soft Reset Command — FE
The SOFT RESET COMMAND command forces the UNILINK Host Adapter to
execute a software reset. All TIWAY I communications will be aborted, all
macros cleared, and the adapter will branch to the beginning of normal
operating routines. The power-up diagnostics will not be performed. The reset
will begin immediately after the response has been sent to the host computer.
Your host applications software should delay issuing another command for a
minimum of 500 ms.
Command: FE
Response: FE