When power is applied to the 3M SelfCheck system, its internal PC runs self diagnostics. If all pass, the system then determines if the ACS requires a special login procedure. This is sometimes required for a connection. For example, the 3M SelfCheck system can be configured to send certain character strings and then wait for certain character strings from the ACS. This is referred to by the 3M SelfCheck system as the “sends/expects”. For example, the system could use the sends/expects settings to do the following:
send a carriage return
wait for "login:"
send a user ID
wait for "Password:"