Welch Allyn Duet CO2 Module - User Manual - Manual (Page 68)

Duet CO
2
Module OEM Implementation Manual
Page 68 Confidential Welch Allyn OEM Technologies
Percent CO
2
Calculation
It is necessary to convert the CO
2
display from mmHg to percent CO
2
in order to compare the
measurement to a calibrated gas, usually marked in percent CO
2
. (There are other user environments
where the preferred units of measure is % CO
2
.) The Host system is responsible to convert partial
pressure (mmHg) CO
2
the corresponding percentage. Typically, calibrated gas measurement is a
steady state measurement, so updated breath data is not necessary. Also, calibrated gasses are dry
gas, therefore the water vapor and BTPS compensations should be disabled by the Host in those
instances where dry gas readings are made.
INITIALIZE BREATH DATA UPDATE RATE
ê
REQUEST AMBIENT BAROMETRIC PRESSURE
ê
DIVIDE ETCO
2
( IN MM H G ) VALUE BY AMBIENT BAROMETRIC PRESSURE ( IN MM H G )
Software Upgrade
Download to FLASH Memory
To load new executive code into the Duet Module via the serial port of a PC, use the inject.exe
application. Welch Allyn OEM Technologies will provide the application when software upgrades are
required. The source code was written in C programming language and consists of four modules:
heart.c, syringe.c, needle.c and serial.c. Inject.exe is designed to run from the DOS command line as
there are timing issues involved with loading the boot code. Inject does not run well under Windows. It
is assumed that an operational DUET Module is connected to a viable serial port and that power is
supplied to the DUET Module for the download to function properly.
The DUET Module is referred to as the “module” in the following section.
Command Line Parameters
The command line parameters, or switches, must be set for inject.exe to work. Because of this, it is
easiest to invoke inject.exe from a batch file. The switches are listed in the following table.
Switches Description
-Fx Inject Fast, where x =
0: the agent is transmitted at 2400 baud
1: the executive loader code, or agent, is sent to the module at
19200 baud
-Cfilename.ext File name of executable code that is to be loaded into the module.
The file is expected to be in a Motorola S1:S9 format which is
explained at the end of this section.
-Rfilename.ext File name that contains the values to be loaded into the registers to
configure the 68HC11.