Ain_ - Analog Inputs - Siemens Moore 353 User Manual

Function Blocks

3.2.9 AIN_ - Analog Inputs

AIN_ function blocks convert a voltage input, having a
range defined during calibration, into a block output signal
that is scaled in engineering units. The output is then
interconnected to other function blocks within the
controller.
A 6-character ASCII value can be entered to identify the
engineering units of the output signal. The scaled output
range is configurable and has a factory default of 0.0 to
100.0 PRCT. Ranges such as 300.0 to 500.0, representing
engineering units in degrees C, can also be configured.
The Output Range is a special data type that includes the
MIN and MAX SCALE, the DPP, and the ENGUNITS
that can be connected to other blocks with a Range (RG
PTR) input.
Analog Input blocks are available on the MPU Controller
Board (CB) and on the I/O Expander Board (EB). Block names (IDs) are listed in Section 8.4 together with the case
rear terminal numbers. Power for 2-wire transmitters is available at the rear terminals.
A digital filter (time constant) is available to dampen process noise. A square root extractor is also available to
linearize a flow signal from a ∆P transmitter, allowing the block output to be configured for flow units. Output QS
indicates the quality of the analog output signal O1, and will be high (1) when output O1 is bad, and low (0) when
good. Bad quality signifies an A/D conversion failure or a 1-5Vdc input signal that falls below 0.6 Vdc indicating
an open circuit or failure of a 2-wire transmitter.
A verify mode is available during calibration to view the analog input, in volts, over the full calibrated range. The
input is factory calibrated for 1-5 Vdc and should not require field calibration. However, field calibration can be
performed if another range is required or to match the exact transmitter calibration. Current inputs are
accommodated using precision dropping resistors connected across the input terminals (250Ω resistors are supplied
with the controller for conversion of 4-20mA inputs).
Power Up - During a hot, a warm or a cold start, the function block will temporarily by-pass the digital filter to
enable the output to initialize at the actual hardware input signal.
xmtr+
AI_+
.
AI_c
3-18
Current Limit
+ 24 Vdc
R1 R2
A/D
C1 C2
BLOCK DIAGRAM
ANALOG INPUT _
AIN_
AIN_+
ANALOG INPUT
AIN_c EXTRACTOR
M I N S C A L E
MINimum SCALE
M A X S C A L E
MAXimum SCALE
D P P
D P P
ecimal t. osition (preferred)
E N G U N I T S
ENGineering UNITS
D I G F I L T
DIGital FILTer
(S)
S Q R O O T
SQuare ROOT extractor
C A L Z E R O
ZERO input
(C)
C A L F U L L
FULL scale input
C A L V I E W
VIEW input - verify cal.
ENG UNITS
NO
Digital
Scaling
Filter
YES
XTR
Quality Test
UM353-1
Output Range
OR
Output 1
O1
Quality Status
QS
.................. Real (0.0)
(H)
................. Real (100.0)
(H)
(S) .. 0.0.0.0.0.0 (0.00)
.. 6 Char ASCII (PRCT)
(S)
............. 0 to 180 sec (0 sec)
.... N0/YES (NO)
(S)
.................. 0 to 1.0 Vdc
...... 4.0 to 5.0 Vdc
(C)
............ Real
(C)
O1
QS
March 2003