Analog Inputs; Math Functions - Honeywell UDC3500 Product Manual

Introduction

Analog Inputs

The UDC3500 has three universal analog inputs with a typical accuracy of ±0.10% of
full-scale input and a typical resolution of 16 bits. These can be configured to act as one
Universal and four High Level Inputs for a total of five analog inputs. All analog inputs
are sampled six times per second (every 166 ms).
The Process Variable input can be one of the various thermocouple, RTD, Radiamatic or
linear actuations. Linear actuations have thermocouple, RTD, and Radiamatic transmitter
characterization capability as a standard feature. Linear actuations also have square root
capability.
The optional second and third inputs are isolated from each other and all other inputs and
outputs and accept the same actuations as input one. Input 3 provides the Slidewire input
for Position Proportional control. These optional inputs can each be split into two high
level inputs. The fourth input is enabled by first configuring Input 2 as a 20 mA or 5 Vdc
type (high level) input and moving a jumper on the Second Optional Input Board. Input 4
will then be available as a high level input. The fifth input is enabled by first configuring
Input 3 as a 20 mA or 5 Vdc type (high level) and moving a jumper on the Third Optional
Input Board. Input 5 will then be available as a high level input.
All actuations and characterizations are keyboard configurable. Cold junction
compensation is provided for thermocouple type inputs. Upscale, downscale or failsafe
sensor break protection is keyboard configurable. A configurable digital filter of 0 to 120
seconds provides input signal damping.
Thermocouple Health—In addition to the standard configurable upscale, downscale or
failsafe output burnout selections, the condition of the thermocouple can be monitored to
determine if it is good, failing or in danger of imminent failure.

Math Functions

Algorithm—Two pre-configured algorithms are available for easy implementation. This
includes the capability of using a Ratio and Bias with any input. You can select from the
following menu:
Feedforward Summer—Uses any input, followed by a Ratio/Bias calculation, summed
directly with the computed PID output value to provide a resultant output to the final
control element (standard feature).
Weighted Average —Computes the weighted average of a PV or SP for the control
algorithm from two inputs (standard feature).
Feedforward Multiplier—Uses any input, multiplied by the calculated PID output to
provide a resultant output, which is sent to the final control element (standard feature).
Summer/Subtractor—Will add or subtract inputs with the result used as the derived PV.
Multiplier/Divider—Uses the analog inputs to calculate a derived PV. It is available
with or without Square Root.
Input High/Low Select—Specifies the PV input as the higher or lower of two inputs.
2 UDC3500 Universal Digital Controller Product Manual 10/05