Abstract: When communication utilizing a first protocol that is normally employed in a network wherein communication can be performed by a plurality of protocols fails, the cause of failure is examined by communication using a second protocol, and communication is recommenced utilizing the first protocol by automatically performing repair. Consequently, communication using the first protocol can be recommenced without interruption of communication, without requiring a correction operation by manual action by the operator.

Abstract: In the method, lines are printed on a sheet using a head unit, the lines having a pitch larger than a printing width of the head unit, the printing width being a width along a first direction. In the method, using the head unit, a first part of a first line is printed on the sheet along a second direction perpendicular to the first direction. A relative position of the head unit with reference to the sheet is moved along the first direction a distance equal to the printing width of the head unit. Using the head unit, a remaining part of the first line and at least a first part of a second line is printed on the sheet along the second direction. The relative position of the head unit with reference to the sheet is moved along the first direction a slight distance equal to or shorter than the printing width of the head unit. Using the head unit, a predetermined part of the second line is printed on the sheet along the second direction, the predetermined part including the first part of the second line.