Det-Tronics EA2100CG Eagle 2000 Communication Gateway - Manual (Page 11)

Section III
EA2200DCU
Digital Communication Unit
APPLICATION
The Eagle 2000 Digital Communication Unit (DCU) digi-
tizes a 4 to 20 ma analog signal from a basic Det-Tronics
gas sensor/transmitter and transmits the value as a pro-
cess variable to the Eagle communication gateway. In
addition to the 4 to 20 ma input, the DCU can also simulta-
neously accept two digital (switch or relay contact) inputs.
All circuitry is housed in a single explosion-proof/water-
tight enclosure for location at the area of detection.
The DCU is provided in various configurations, depend-
ing on the type of gas to be detected. (DCUs are avail-
able for use with combustible gas, oxygen and toxic gas
sensor/transmitters.) All DCUs contain a communications
module and a terminal wiring board. DCUs for detecting
combustible gas also contain a transmitter board.
FEATURES
• Field addressable
• Fault isolation
• Pass through communication circuitry on power loss
• 10 bit signal resolution
• 2 alarm setpoints
• Sealed 5 ampere SPDT relay
• Non-volatile memory for logging of alarm and cali-
bration events
• Non-intrusive one person calibration
• LED for calibration, fault and alarm status annunciation
• EMI hardened
• Screw terminal connectors.
SPECIFICATIONS
INPUT VOLTAGE—
18 to 32 vdc.
INPUTS—
4 to 20 ma analog signal, with an input impedance of
200 ohms in series with a protection diode. Two digital
contact inputs (switch or relay contacts). One is dedi-
cated to detector calibration. The other is available for
general use, with either a normal or inverted input.
OUTPUTS—
Digital communication, transformer isolated (78.5 kbps).
Calibrated 0 to 4095 digital output corresponds to 0 to
full scale current input. Twelve discrete points of status
and diagnostic information are also sent to the gateway.
One SPDT sealed relay, rated 5 amperes resistive at 30
vdc, is activated when the “alarm 1” threshold is reached.
The relay is latching and is reset by the host device when
the process variable is below the alarm threshold.
POWER CONSUMPTION—
DCU with toxic sensor/transmitter:
95 ma maximum during normal operation with relay
energized or during startup.
DCU with transmitter and combustible gas sensor:
180 ma maximum during normal operation with
relay energized, 500 ma during startup.
TEMPERATURE RANGE—
Operating: –40°F to +167°F (–40°C to +75°C).
Storage: –67°F to +185°F (–55°C to +85°C).
SHIPPING WEIGHT (Approximate)—
2.2 lb (1.0 kg).
DIMENSIONS—
See Figure 8.
7 95-8424
RELAY
RELAY
ALARM
RELAY
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
DO NOT RUN WIRES IN THIS AREA.
KEEP CLEAR FOR RIBBON CABLE CONNECTOR.
A1556
MAGNETIC SWITCH * EARTH GROUND TERMINAL
Figure 7—Terminal Wiring Board Installed in Junction Box
* TO ACTIVATE THE REED SWITCH, HOLD THE MAGNETIC CALIBRATION TOOL AGAINST
THE SIDE OF THE ENCLOSURE MIDWAY BETWEEN THE TWO MOUNTING HOLES,
APPROXIMATELY AN INCH ABOVE THE MOUNTING SURFACE FOR COMMUNICATION
MODULES, UNIVERSAL DCUs AND COMBUSTIBLE GAS DCUs, AND APPROXIMATELY
3 1/2 INCHES ABOVE THE MOUNTING SURFACE FOR INTRINSICALLY SAFE DCUs.