Siemens SIMATIC TIWAY 1 - Manual (Page 32)

OPERATION AND APPLICATION
UNILINK HOST ADAPTER 2–22
USER MANUAL
2.8 MODE INDEPENDENT OPERATIONS
The mode independent commands perform hardware and software resets, and
external I/O point operations regardless of the operating modes.
2.8.1 Reset Commands
There are two reset commands that can be sent to the UNILINK Host Adapter
regardless of the operating mode. The reset commands should be used
cautiously because they clear all macros and configuration parameters, and
discard any outstanding operations on the network. The first is the SOFT
RESET command, code FE. This command causes the adapter to execute a
software reset operation. All current TIWAY I operations will be aborted and the
adapter will go into a startup state without performing power up diagnostics.
The command code will be returned as a response and the reset will begin
immediately after sending the response to the host. Your applications software
should not issue another command for at least 500 ms.
The second reset command is the RESET ADAPTER command, code FF. The
reset will begin within one second after the reset command response is returned
to the host. Your applications software should allow an additional five second
delay before issuing another command to allow the diagnostics to complete.
The response to either reset command will not be returned until the adapter is
polled when using the host BDLC protocol. Chapter 3 provides more
information on host interface protocols.