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Technical Specifications

Inputs

Two 4-20 mA inputs sharing a common ground and two discrete contact closure inputs (Model WI-AI)

Wireless Instrumentation

Two 0-10 V inputs sharing a common ground and two discrete contact closure inputs (Model WI-AV)

Multi-Input Field Unit - 23702 Multi-Input Field

Input Characteristics

10 Ohm impedance, analog (WI-AI) 100 kOhm impedance, analog (WI-AV)

Output Characteristics

See the Base Radio description for analog and digital output

options Accuracy

0.1 % of Full-scale reading at reference conditions Ambient Temperature Effect = 0.01% of reading per C

Sampling and Transmission Characteristics

The Multi-Input Field Unit samples analog signals (4-20 mA or 0-10 V) at regular intervals. The data may then be transmitted to the Base Radio for centralized monitoring and data acquisition. The user specifies how frequently the process is monitored and how often data is transmitted. Input 1 and Input 2– user designates low rate and high rate conditions Sampling rate– user selectable from 1 to 60 seconds (low rate) and from 1 to 30 seconds (high rate) Transmission rate– user selectable from 1 second to 60 seconds (low and high rate) The Wireless Instrumentation Manager can be used for real-time monitoring of the process information. The user can set thresholds to represent “alarm” or abnormal conditions.

Multi-Input Field Unit Description

Local Configuration

The Multi-Input Field Unit is ideal for adding wireless capabilities to existing or new wired measurement sensors such as radar tank gauges, flow meters, chemical analyzers, or any other de-vice that has voltage or current outputs. The Multi-Input Field Unit is available in current (4-20 mA), voltage (0-10 V), or milli-volt (0-1000mV) versions, each accepting up to two analog in-puts. Each model also includes two discrete contact closure inputs (for simple apparatus). A variety of packages are also available to fit the field environment ranging from NEMA 4 or 4X to NEMA 7 Explosion Proof for integration to field instruments not rated intrinsically safe. The XP housing can also be used to provide field 24 VDC power (if available) in lieu of standard bat-tery power. The Field Unit is an integrated input module, signal conditioner and RF transceiver with self-contained power operating in the 902 MHz to 928 MHz ISM license-free band. Rated intrinsically safe, it is approved for use in all hazardous areas. Optional output switches can also be provided to perform on/off control in the field based on programmable input set point. Output switch option for ordinary area classification only. The versatile Multi-Input Field Unit can accept conditioned sig-nals or raw sensor inputs. Using the 22 point offset curve, transducer outputs can be converted into meaningful engineer-ing units with non-linear curves that are user programmable. Integrated LCD display with membrane switches Display rotates through Input 1, Input 2 and error messages, if applicable Configure sampling and RF parameters locally using membrane switch buttons
Wireless Instrumentation WI-AI AV Product Description 08/29/07

Power Characteristics

Self-contained, ‘C’ Size 3.6 V lithium battery Up to twenty (20) year battery life (depends on sample rate and RF update rate), field replaceable

RF Characteristics

902 MHz – 928 MHz Frequency Hopping Spread Spectrum (FHSS), FCC certified ISM license-free band Up to 3000’ range from Base Radio with clear line of sight; 500’ to 1000’ range with obstructions The RF module in each Field Unit is individually tested and calibrated over the full temperature range to ensure reliable wireless operation

Self-Diagnostics

Low battery alarm– indicates the need to replace the battery (approximately one month warning) Contains extensive self-checking software and hardware that continuously monitors the operation. Any sensor or device parameter out of spec is identified and reported