IBM TM7 - Manual (Page 47)

RS-232 Communication Mode Selections
Switch settings described in this section apply only when the printer is connected to
the system with the RS-232 cable. The switch is accessible without removing the
printer covers. (See Figure 4 on page 12 to see how to access the switch.)
Baud Rate Selection
SureMark printers support two RS-232 baud rates, 9600 and 19 200. The baud rate
is selected using switch 1 on the RS-232 settings switch. Set the switch as follows:
Switch 1 OFF 9600 baud
Switch 1 ON 19 200 baud
The printer normally ships with switch 1 in the OFF position, which selects the 9600
baud rate.
RS-232 Communications Protocol Selection
SureMark printers support RS-232 protocol using either DTR/DSR or XON/XOFF to
control data transmission. XON/XOFF mode uses system and printer software to
control the flow of data.
Use switch 2 on the RS-232 settings switch to select the mode. Switch settings are:
Switch 2 OFF DTR/DSR control
Switch 2 ON XON/XOFF control (must use with a 3-wire interface)
The printer normally ships with switch 2 in the OFF position, which selects
DTR/DSR control.
DTR/DSR Control
DSR Definition: DSR is an output from the printer. It indicates when the printer is
ready to receive data.
DTR Definition: DTR is an input to the printer. It indicates to the printer that the
system is ready to receive data.
DSR Operation: A DSR signal becomes inactive when the printer is not ready to
receive data (for example, at power-on reset or when its buffer is full).
updated March 18, 2002
Chapter 2. Installation Instructions 23