Emerson Process Management 3420 Carbon Monoxide Alarm User Manual


 
26 Hardware features
Section 2: Product overview Reference, Installation, and Operations Manual
June 2013 3-9000-743 Rev S
2.5 Hardware features
2.5.1 Inputs
Digital input
The meter provides a single general-purpose digital input. The input signal polarity is selectable
via a configuration data point and its (polarity-configured) value is readable via another data
point.
Pressure and temperature analog inputs
The meter provides two analog inputs (AIs) via the Option Board or the Series 100 Plus Option
Board - one for temperature (AI1) and one for pressure (AI2). Each analog input is expected to
be a 4-20mA signal.
The analog-to-digital conversion accuracy is within ±0.05% of full scale over the operating
temperature range.
2.5.2 Outputs
frequency Outputs
The Daniel Mark III Ultrasonic Gas Flow Meter provides two pairs of frequency outputs where
each pair is individually configurable. The first pair is comprised of FO1A and FO1B; the second
pair is comprised of FO2A and FO2B. The information represented by each frequency pair is
software selectable (with selections such as flow volume, gas velocity, sound velocity, energy
rate, or mass rate - see Section 5.6.7). The frequency output range for each pair is individually
software selectable as either 0-1000 Hz or 0-5000 Hz (with an overrange of 50%).
The worst case frequency output granularity is 1 Hz at 5000 Hz. When a frequency is configured
to represent volume, the volume accuracy is within ±0.01%.
The meter provides two pairs of configurable frequency outputs (FO1A, FO1B, FO2A, and
FO2B), four configurable digital outputs (DO1A, DO1B, DO2A, and DO2B), and an optional
analog output (AO1).
The frequency and digital outputs are divided into two groups as follows:
Group 1:FO1A, FO1B, DO1A, DO1B
Group 2:FO2A, FO2B, DO2A, DO2B