ABB Symphony Harmony Series, Инструкция, Страница: 190 / 402

Function Codes
WBPEEUI240751C0 6 - 11
I/O Channel Data
An I/O channel function code reports channel data in auto-
matically generated exception reports. Channel data includes
quality, alarm status, channel status, analog value or digital
state, and a time-stamp. The data can be read by an external
device such as a human system interface. The information is
also available at the I/O channel function code outputs, which
can be accessed by other local function codes.
Quality
The quality reported by an I/O channel function code is either
good or bad as determined by the function code.
Alarm Status
For an analog channel, the alarm status indicates that the
value being reported is within normal limits or has reached or
passed either a high alarm or low alarm limit. The alarm limits
are defined in I/O channel function code specifications.
For a digital channel, one of its two digital states can be
selected as an alarm state. The alarm state is selected with an
I/O channel function code specification. When the channel
toggles to the selected alarm state, an alarm is reported.
Channel Status
Channel status is reported in the form of problem reports
which appear on a human system interface. Refer to
Section 8
for channel problem report details.
Value or State
The analog value is reported in IEEE real-4 format. The digital
state is reported as either a boolean logic one or zero.
Time-Stamp
The time-stamp is the system time at which a value was read.
The time is in milliseconds.
Suspect Condition
The function code tests redundant inputs and outputs to
determine suspect condition, and it also tests actual value
against an override or simulated value. Actual value refers to
an input value for analog or digital inputs and a demanded
output value for analog or digital outputs. For analog inputs
and outputs, the suspect indication is controlled by the devia-
tion limit specification set in the I/O channel function codes
(refer to Table
6-2 ).
NOTE: Only readback capable digital outputs can indicate suspect while in nor-
mal mode. The DOT-100 block does not support readback.