Design And Implementation Of Hc900 Control System; Allowable Function Blocks For Process And Safety Functions; Table 4 - Function Blocks - Honeywell HC900 Safety Manual

Design and Implementation of HC900 Control System

Refer Installation guide section "Design and implementation"

Allowable Function Blocks for Process and Safety Functions

The following table lists the function blocks which are allowed in the safety portion and the function blocks
which are allowed in the process control portion of an HC900 controller configuration.
Category and
Function block Description of Function
Name
I/O Blocks
Reads value of an Analog Input from a specified
Analog Input
physical I/O address.
Analog Input with This block is used only for Thermocouples when the
Remote Cold thermocouple Cold Junction is in a remote location,
Junction i.e, NOT connected at the AI module.
Reads values of up two to three Analog Inputs from
Analog Input with specified real I/O addresses. Function block value
Voting
reflects channels that are within tolerance (3%) of
each other.
The output range high and range low values (0-20
Analog Output
max) set the milliamp output values that correspond
to the 0 to 100% span limits of the inputs.
The output range high and range low values (0-20
max) set the milliamp output values that correspond
Analog Output
to the 0 to 100% span limits of the inputs. Feedback
with Feedback
channel validates physical output is within tolerance
(3%)
Provides the digital status of a digital input point and
Discrete Input
provides interface to other algorithms and functions.
Provides the digital status of a digital input point and
provides interface to other algorithms and functions.
Discrete Input
Compares up to three inputs, function block output
with Voting
reflects the majority of valid input channels. Physical
input channels must be the same model no.
8 Point Digital
Provides read access for up to 8 physical digital
Input
inputs (all read at the same time).
Revision 1.9
01/14
Table 4 – Function Blocks
HC900 Process & Safety Controller Safety Manual
Can FB Can FB
be used be used
in a as a
safety- process
related control
function? FB?
X
X X
X
X X
X X
X X
X X
X X
X
FB that
can't be
used in
safety
config-
uration
X
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