Interfaces7–12
ACK/NAK
– W
ith ACK/NAK protocol selected, the
printer responds as described for ETX/ACK pro
-
tocol
except the printer monitors the received data for parity error
. If a parity error is detected, a NAK
character
is transmitted to the host upon receipt of the ETX character
. The host is expected
to repeat the
data
transmission.
RS–232
INTERF
ACE ERROR
– W
ith an odd or even parity check
in ef
fect, the detected character
error
shall be replaced with a question mark (?). If a parity error is detected, a NAK character (hex 15)
is transmitted to the host when the ACK/NAK protocol is selected. When parity is not checked, parity
errors are ignored and the characters are printed as received. Parity checking is a configuration option
selected from the control panel. When a framing error occurs, an
exclamation
point (!) prints. When a
data
overrun error occurs, an asterisk
(*) prints. After 20 successive errors have been received, a line
feed is added which forces printing to occur.
RS–232 Serial Interface Configuration
The
printer is configured at the factory
. However
, the configuration is also user selectable. The follow
-
ing
configuration parameters can be verified or changed as necessary to meet specific application re
-
quirements:
•Data Protocol of hardware (DTR, Reverse Channel, or RTS), or X–ON/X–OFF, ACK/
NAK or ETX/ACK
•Data Rate (baud rate selected from the control panel)
•
Data W
ord Length (7 or 8 bits)
•Stop Bits (1 or 2 bits)
•Parity (odd, even, or none)
•Bit 8 Function (font select, PI line, or ignore)
•CD and CTS signal (enable or disable)
•DSR signal (enable or disable)
•Data T
erminal Ready response logic
•
Request to Send response logic
•
Reverse Channel response logic
These parameters are displayed under the Application Compatibility/Host Interface/Serial RS–232
submenu
selectable from the control panel. Refer to the Control Panel Configuration diagram in the
Configuration chapter for detailed information on selecting the various parameter values.
NOTE:
Do not use the bit 8 function to set the PI line if the
host does not use it for paper
control;
rapid paper slewing may occur
.