Siemens SIMATIC TIWAY 1 - Manual (Page 13)

OPERATION AND APPLICATION
UNILINK HOST ADAPTER 2–3
USER MANUAL
Host
Computer UNILINK
Host Adapter
Commands
Responses
Secondary
Secondary
Figure 2–3 Host Computer To UNILINK Host Adapter
Communications
Commands are checked for errors before they are executed. The ERROR
RESPONSE is a special response that returns a code indicating the type of
error. If an error is found, the command will not be executed and the ERROR
RESPONSE will be returned. The ERROR RESPONSE will also be returned if a
network request does not complete within the host command timeout. The
possible error codes that may be returned in the ERROR RESPONSE and
corrective actions to take are listed in Chapter 6.