Welch Allyn LC101 CO2 Module - User Manual - Manual (Page 42)

LC101 CO
2
Module OEM Implementation Manual
Page 42 Confidential Welch Allyn OEM Technologies
• Hard Reset - If the host holds the receive data line in a break condition for more than
500 msec, the microprocessor is forced to enter the boot mode when the break
condition is released. The microprocessor boot mode is used to install new software
into the FLASH device.
Internal Resets (Initiated within the LC101 Module)
• Watchdog Reset - Watchdog reset is caused by a watchdog timeout. After a
watchdog reset, the Module responds to a Request Status command with the
status response (fault mode, watchdog timeout). The host must issue a reset
to recover from a watchdog reset.
• Self Reset - Caused by a condition other than watchdog timeout. After self reset, the
Module responds to a Request Status command with status response
(fault mode, status OK). The host must issue a reset to recover from self
reset.
System Behaviors - Dynamic Communications
Status Requests
The host must poll the LC101 Module periodically to determine status. By sending status
requests, the host can report any problems seen by the LC101 Module.
WARNING The host should NOT assume that if waveform data is being sent by the LC101
Module, the LC101 Module is not reporting any errors. It is possible to report
a non-fatal error condition even when waveform data is being sent.
When the LC101 Module is in 'Fault' mode, it will report the error that caused the fault.
CO
2
Waveform Data
During 'Measurement' and 'Autorun' modes, the LC101 Module sends a CO
2
waveform packet
every 31 msec (or every xx number of 31 msec increments if the Nxx command was used). Also,
the LC101 Module will be responding to the host's periodic requests for status data. The host
may experience a delay in the waveform packet timing, but the delay will be made up by the
increased delivery speed of the next few packets.
If waveform data ever stops being sent, the status response will inform the host of a fault
condition. The fault condition could leave the LC101 Module in 'Fault' mode (i.e., ) or the
LC101 Module could remain in 'Measurement' or 'Autorun' mode (e.g., if a "No Watertrap" status
message is returned).
"No Watertrap" Status Messages
During 'Measurement' and 'Autorun' modes, the LC101 Module will continually verify that a
watertrap is present. If the watertrap is NOT detected and a status request is received, the
status message "No Watertrap" will be returned. No waveform data will be sent at this time.
Regardless of the operating mode, this status message will be returned until a watertrap is
inserted, the host sends a mode change command, or a fault event is detected.