I agree that this is talking about a kind of program routine. "one cycle" may be an option for "1周",　but "circle" also makes sense.

This is not my field and I’m just surmising based on what I've found online, but to start, “周遊” means “round-trip.” (though this is not the round-trip about computers.) :-)

Here are some websites that define or use the word “round-trip” as related to computers.

http://en.wikipedia.org/wiki/Ping

Ping is a computer network administration utility used to test whether a particular host is reachable across an Internet Protocol (IP) network and to measure the round-trip time for packets sent from the local host to a destination computer, including the local host's own interfaces.

The output then shows the results of making 10 pings to 66.230.200.100 with the results summarized at the end. (To stop the program in Linux or Windows, press Ctrl+C.)
 shortest round trip time was 78.162 milliseconds
 average round trip time was 89.213 milliseconds
 maximum round trip time was 97.695 milliseconds
 Standard deviation of the round-trip time was 6.836 milliseconds
http://www.yourdictionary.com/computer/round-trip
round trip computer definition
round trip
From the source to a destination and back to the source again. See also round tripping

http://www.yourdictionary.com/computer/round-tripping
round tripping computer definition
round tripping
The capability of converting data into a different structure and converting it back to its original without loss. For example, with a native XML database, an XML document can be stored and retrieved intact without any loss of data. See XML database.

Would be more confident with context.