Honeywell HC900 Safety Manual page 41

Design and Implementation of HC900 Control System - Allowable Function Blocks for Process and Safety Functions
Reads the numerical value of a selected configuration
parameter in a given function block. Select the index
number of the required parameter from the specific
function block reference data, and enter it in the
appropriate field in the "Read Constant Properties"
dialog box. The main purpose of this control block is
to make a block configuration parameter (constant)
available for display. To do this, you must enter the
Read Constant
corresponding parameter index number for the
selected configuration parameter. Select the index
number of the required parameter from the specific
function block reference data and enter it in the
appropriate field in the "Read Constant Properties"
dialog box. When used in a safety worksheet the
specific function block must also be on a safety
worksheet.
Writes the numerical value of a selected configuration
parameter to a given control block. Select the index
number of the required parameter from the specific
function block reference data and enter it in the
appropriate field in the "Write Constant Properties"
Write Constant
dialog box. If EN is ON, change the selected
parameter to the value of X. ATTENTION: Not valid
for all blocks. Write constants into a safety worksheet
function block is only permitted when operating in the
"RUN/PROGRAM" or "PROGRAM" modes
Writes a new value to a selected Variable number.
Select the target variable number from the specific
function block reference data and enter it in the
appropriate field in the "Write Variable Number"
Write Variable dialog box. If EN is ON, then the Variable selected is
set to the value of X. (For example: X = a constant
value). Wrtie variablles into a safety worksheet
function block is only permitted when operating in the
"RUN/PROGRAM" or "PROGRAM" modes
Provides an output that tracks the value of the input
(X), when a digital input signal (TC) is On; or when
Track and Hold TC is OFF, holds output at last value of X. If TC =
ON, then: OUT = X (TRACK). If TC = OFF, then: OUT
= Last value of X (HOLD).
Accepts up to 8 digital inputs in sequence and
interprets the ON/OFF status of the first 4 inputs as a
BCD Translator
BCD value between 0 and 9 and the second 4 digits
as a value between 10 and 80.
This block's main function is to totalize the number of
ON states from up to 16 digital signals. The block
digitally encodes up to 16 digital inputs to a single
Digital Encoder
floating point output value. Sixteen digital inputs:
Example: ON causes the input to be included in the
total output. Unconnected pins default to OFF.
Forcing of the output is not permitted.
Revision 1.9
01/14
HC900 Process & Safety Controller Safety Manual
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