Owner`s manual

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1.4.4 V79 PDI-1 AND V80 PDI-2
COMMANDS AND DATA PRESENTATION
The PDI-1 and PDI-2 have sixteen input channels
capable of sensing, recording, and reporting information
from dry contact closures (PDI-1) or optically isolated
inputs (PDI-2). A module can observe, record, and
report when an event happened, how long the event
lasted, and how many events occurred. An event is
defined as a change-in-state of an input from LO to HI
(or vice versa) and return to the original state. A
debounce delay can be selected to reduce the effects of
short term transitions such as noise or contact bounce.
Latch polarity, which is user selectable, determines
which transition (LO to HI, HI to LO, or both)
constitutes the start of an event. The state and start
time of an event are buffered for transmission to the
user. The event start also starts the duration counter,
increments the event counter and sets an event latch
bit. The duration counter measures event duration time
in milliseconds with a maximum time of 65,535 stored.
The event counter reflects the total number of events
that have occurred since the last time a CCc (Clear
Event Counter) or ROc (Report Event Counter and Reset)
command was sent. The initial occurrence of an event
sets the event latch and store the associated time.
There are three methods of reporting data: Command,
Schedule, and Immediate. Command reporting allows
the user to send commands to report the event counter,
event duration, event latch, the current state, the most
recent event, or buffered event samples. The command
table on Page 19 summarizes the commands supported
by the PDI-1 and PDI-2.
The immediate and schedule reporting methods provide
auto-reporting of events. When the immediate method