CONFIGURATION
The 7823 may be reconfigured at any time by
adjusting the position of the header pin jumper links on the
interface PCB.
WARNING
: Prior to re-configuration the 7823
MUST
be powered down. The jumper links
MUST
also be
repositioned correctly and in the correct orientation.
Failure to adhere to the above could result in product
damage. Products damaged due to incorrect
configurations will not be covered under warranty.
Power down the 7823
Remove the lid using a Philips screwdriver
Adjust the position of the jumper links to the desired
configuration. The diagrams below and on Page 4
show the correct positioning for each user
configurable option. Thin nosed pliers should be
used to remove and replace the Jumper Links.
Ensure the Jumper Links are correctly seated before
reapplying the power
NOTE: Each Jumper Link must be placed in one of the two
positions. When selecting the output, you must choose
either 4-20mA and 0-10V
DC
or RS232 Tx and Rx. Ensure
the Jumper Links are always inserted horizontally between
2 adjacent pins.
RS232 OPERATION
With the 7823 RS232 outputs connected to a PC or
any other RS232 compatible device the user has the
ability to access two modes of operation, continuous data
streaming and the menu screens. Recommended
programs for communicating via PC serial RS232 are
Hyperterminal (windows default), Teraterminal and PuTTY.
A freeware PuTTY link can be found below;
http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe
Continuous Data Streaming
On power up, after the initial 60s heater delay, the 7823
will automatically begin outputting the measured O
2
concentration and sensor Td as both an averaged and raw
value. The averaged values give a stable output with the
amount of averaging user variable whilst the raw un-
averaged values allow the user to detect sudden oxygen
changes. The averaged value is the measurement output
on both the 4-20mA and 0-10V
DC
outputs. The sensor Td
value is the measure of the partial pressure of oxygen in
the measurement gas. The O
2
concentration (%) is the Td
value scaled by the stored calibration value.
To stop or restart the data streaming ‘s’ (lower or upper
case) should be sent to the unit. Data streaming
automatically ceases during calibration.
Menu Screens
If the 7823 receives an enter character from the
connected PC or device it automatically enters the menu
password screen and stops outputting O
2
% and Td
values. After the correct password is entered followed by
the enter character, the menu screens are accessed. The
menu screens are primarily for diagnostics and information
although there are user configurable options that may be
changed. These are the automatic O
2
calibration %, the
amount of output filtering (averaging) and the analogue
output ranges. All three processes are further described
on Page 8. The menu access password may also be
changed by the user.
Changing the Menu Access Password
The password is factory set to ‘
default’
. This however may
be changed to a user specific password.
Connect the 7823 via the RS232 interface to
the PC.
Press Enter then enter your current security
password. Press Enter to access the menu screen.
In the Configuration menu (menu 2) enter ‘3’ to
access the password menu screen.
Enter the new password then press Enter to save.
The new password is now stored in memory and is
retained on power loss.
Pressing ESC returns the screen to the previous menu.
7823
Oxygen Analyser
ECO
line
7823 Oxygen Analyser
E instruments
Page
7
of 12
