If this service is frozen or simply not running you will get an error indicating that there was a failure communicating with the autosequence pc.
A lot of the time if the service is frozen you will simply have the pos operations hang for a few minutes before the error displays, if the service is not running you should get the error almost instantly.
RES 3.2 and below:
The autosequence service is located in the Micros Control Panel and can be turned on or off.
RES 4.0 and above
The autosequence service is located in windows services and is called "Micros Autosequence Service". If it is stopped start it, if it is started then restart it.
If you are unable to restart the service you will need to kill the executable via task manager or 3rd party program such as pskill.exe which can be downloaded from microsoft.com.