Epson Action Laser II - Manual (Page 91)

SelecType Options
X O N / X O F F O N
*ON
OFF
This option turns the XON/XOFF communications protocol on or
off. XON/XOFF protocol can be used in combination with the DTR
option setting.
ENQ/ACK OFF
ON
“OFF
This option is available in the Epson GL mode only.
DSR OFF
ON
*OFF
When DSR (Data Set Ready) is off, the signal level is permanently set
HIGH, allowing the printer to send data to the computer. For most
communications purposes, this option should be set to off (signal
level HIGH). When DSR is on, data is sent to the computer only
when DSR is HIGH.
SelecType 4-27