is the menu selection. Press “UP” repeatedly until the serial interface menu is
indicated with “
SErIAL
”. Finally press “SET” to enter the serial interface pa-
rameters menu. In the serial interface parameters menu are the baud rate, sam-
ple rate, duplex mode, and linefeed parameters.
10.1.2.1
Baud Rate
The baud rate is the first parameter in the menu. The display prompts with the
baud rate parameter by showing “
BAUd
”. Press “SET” to choose to set the
baud rate. The current baud rate value is displayed. The baud rate of the serial
communications may be programmed to 300, 600, 1200, or 2400 baud. The
baud rate is pre-programmed to 2400 baud. Use “UP” or “DOWN” to change
the baud rate value. Press “SET” to set the baud rate to the new value or
“EXIT” to abort the operation and skip to the next parameter in the menu.
10.1.2.2
Sample Period
The sample period is the next parameter in the menu and prompted with
“
SAnPLE
”. The sample period is the time period in seconds between tempera-
ture measurements transmitted from the serial interface. If the sample rate is set
to 5, the bath transmits the current measurement over the serial interface ap-
proximately every five seconds. The automatic sampling is disabled with a
sample period of 0. Press “SET” to choose to set the sample period. Adjust the
period with “UP” or “DOWN” and then use “SET” to set the sample rate to the
displayed value.
10.1.2.3
Duplex Mode
The next parameter is the duplex mode indicated with “
dUPL
”. The duplex
mode may be set to half duplex (“
HALF
”) or full duplex (“
FULL
”). With full
duplex any commands received by the bath via the serial interface are immedi-
ately echoed or transmitted back to the device of origin and the command is ex-
ecuted. With half duplex the commands are executed but not echoed. The
default setting is full duplex. The mode may be changed using “UP” or
“DOWN” and pressing “SET”.
10.1.2.4
Linefeed
The final parameter in the serial interface menu is the linefeed mode. This pa-
rameter enables (“
On
”) or disables (“
OFF
”) transmission of a linefeed charac-
ter (LF, ASCII 10) after transmission of any carriage-return. The default setting
is with linefeed on. The mode may be changed using “UP” or “DOWN” and
pressing “SET”.
10.1.3
Serial Operation
Once the cable has been attached and the interface set up properly the control-
ler immediately begins transmitting temperature readings at the programmed
rate. The serial interface operates with 8 data bits, 1 stop bit, and no parity. The
set-point and other commands may be sent to the bath via the serial interface to
6331 Calibration Bath
User’s Guide
58
