time, and operator time adjustments.
2.1.3.8
Scheduling
a.
Individual controlled equipment shall be schedulable with schedule
based on time of day, day of week, and day of year. Equipment may
be associated into groups. Each group may be associated with a
different schedule. Changing the schedule of a group shall change
the schedule of all equipment in the group. Groups may be
modified, created and deleted by the operator.
b.
Provide capability to view and modify schedules in a seven-day
week format. When control program does not automatically compute
holidays, provide capability to enter holiday schedules one full
year at a time.
2.1.3.9
Point Override
I/O and virtual points shall accept software overrides to any possible
value.
2.1.3.10
Alarming
I/O points and software points shall be alarmable. Alarms may be enabled
and disabled for every point. Alarm limits shall be adjustable on analog
points. Controllers connected to an external communications device such as
a printer, terminal, or computer, shall download alarm and alarm message
when alarm occurs. When a computer workstation is connected to a DDC system
with a LAN or modem, operator selected alarm conditions will initiate a
call and report to the computer [or an alphanumeric pager]. Otherwise
alarms will be stored and automatically downloaded when a communications
link occurs. The following conditions shall generate alarms:
a.
Motor is commanded on or off but motor status input indicates no
change
b.
Temperature, humidity, or pressure strays outside selectable limits
c.
An analog input takes a value indicating sensor failure
d.
A module is not communicating on the LAN
e.
A power outage occurs
2.1.3.11
Messages
Messages shall be operator defined and assigned to alarm or status
conditions. Messages shall be displayed on the workstation or printer when
these conditions occur.
2.1.3.12
Trending
DDC system shall have the capability to trend all I/O and virtual points.
Points may be associated into groups. A trend report may be set up for
each group. The period between logging consecutive trend values shall
range from one minute to 60 minutes at a minimum The minimum number of
consecutive trend values stored at one time shall be 30 per variable. When
trend memory is full, the most recent data shall overwrite the oldest data.
Trend data shall be capable of being uploaded to computer. Trend data
SECTION 15910N
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