Figure 9-5.--Line printer.
DATA LOGGING.--The data logging func-
commanded to print. Figure 9-5 shows a detailed
tion provides a record of the values and/or status
of all parameters of interest, either automatically,
at selected time intervals, or upon operator
The bell logger prints only bell signals and
ALARM LOGGING.--The alarm logging
replies to those signals. Bell signals include
function provides a permanent record of all
rpm commands, pitch commands, and station in
changes in alarm conditions as they occur, in-
control status. All other logging functions are
cluding both the alarm itself and its acknowledge-
done by the data logger.
ment or reset.
STATUS CHANGE LOGGING.--The status
change logging function records nonalarming
The data logger is responsible for all logging
changes in the discrete status of certain param-
functions not performed by the bell logger. These
eters, such as pump on/off or pump fast/slow.
functions include data logging, alarm logging,
TREND LOGGING.--The trend logging
status change logging, trend logging, and demand
function provides continuous and automatic