Epson SQ-2550 User Manual page 278

Commands Arranged by Topic
The last three bits of d2 determine the characteristics of the
score line as shown below:
On (1)
Off (0)
Note: If Bit 1 and Bit 0 are both off, the selected score is
cancelled. Double line and single line scores cannot be
combined at the same score position.
9-34 Commend Summary
Bit 2
Broken
line
Continuous
line
Bit 1 Bit 0
Double Single
line on
line on
Double Single
line off line off