Digital Communication Unit

Product catalog summary

Overview: The Digital Communication Unit (DCU) is a device for addressable gas detection, converting analog signals from sensors into digital signals for controllers. It is housed in an explosion-proof, watertight enclosure and is compatible with various gas sensors, including those from Det-Tronics and third-party devices.

Features:

Field addressable with patented fault isolation.
Advanced communication technology with pass-through capability during power loss.
Ten-bit signal resolution and two alarm setpoints.
Non-volatile memory for event logging and non-intrusive calibration.
LED indicators for calibration, fault, and alarm status.
EMI hardened and compatible with Eagle Quantum systems.

Specifications:

Input Voltage: 24 VDC (18 to 32 VDC operating range).
Inputs: 4 to 20 mA analog signal with 200 ohms impedance.
Outputs: Digital communication, transformer isolated.
Power Consumption: 95 mA max for toxic gas sensors; 180 mA normal, 500 mA startup for combustible gas sensors.
Temperature Range: Operating from -40°F to +167°F; Storage from -67°F to +185°F.
Certification: FM/CSA, CENELEC/CE, ATEX/EMC compliant.
Shipping Weight: Aluminum 6 lb, Stainless Steel 10 lb.

Installation and Operation:

The DCU is installed in a digital communication loop with shielded twisted pair wire.
Calibration and event logging are facilitated by non-intrusive methods and stored in non-volatile memory.
Fault-tolerant network design allows for continued operation despite wiring faults.
Addressability is set via DIP switches, with a range from 5 to 250.

Safety and Maintenance:

Ensure the area is free of combustible gases before applying power with the cover removed.
Use appropriate grease for sensor threads to prevent damage.
Follow specific guidelines for sensor separation and wiring to maintain system integrity.

Guidelines for Separating Combustible Gas Sensor from DCUEX:

Preferred Method: Mount the transmitter PC board inside the sensor separation junction box, allowing separation from the DCUEX by up to 1000 feet using a three-conductor 18 AWG shielded cable. Ensure operating voltage at the transmitter is at least 18 VDC. Assemble the DCUEX without the transmitter board and connect the sensor to P2 on the transmitter board. Use the shielded cable to connect P1 on the transmitter board to terminals 2, 3, and 4 on the DCU terminal board. Connect the shield to the ground terminal in the DCUEX junction box.

Alternate Method: If the transmitter board must be mounted separately from the sensor, leave the transmitter PC board inside the DCUEX enclosure. Mount the sensor directly to the separation kit junction box and use a three-conductor shielded cable for the connection. Follow the wiring color code and connect the shield to the ground terminal in the DCUEX junction box. Refer to Table 2 for maximum wiring distances.

Ordering Information: Specify the EQ2200DCU Ex or EQ2200DCU based on the application. Choose enclosure material (aluminum or stainless steel), number of ports (5 or 6), port size (3/4 inch NPT or 25 mm), and certification (FM/CSA/CENELEC/CE). For assistance, contact Detector Electronics Corporation.

Specifications: Subject to change without notice. For further details, contact Detector Electronics Corporation.

Figures and Tables: Figures 9 and 10 illustrate the connection setups. Table 2 provides maximum separation distances for the alternate method based on wire size.

Catalog excerpts

The Digital Communication Unit (DCU) offers a conve-nient and economical means of obtaining address- able gas detection. The DCU digitizes a 4 to 20 ma analog signal from a sensor/transmitter and transmits the value as a process variable to the controller. 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,depending on the type of gas to be detected. All DCUs contain a communication module and a termi- nal wiring board. DCUs for detecting combustible gas also contain a transmitter board. The DCU is available for use with Det-Tronics com-bustible gas, oxygen and toxic gas sensor/transmit- ters. The DCU can also be used with a wide variety of ғthird party 4 to 20 ma analog instruments. > 24 vdc. Operating range is 18 to 32 vdc. INPUT VOLTAGEԗ INPUTS 4 to 20 ma analog signal, with an input impedance of 200 ohms, 10 bit resolution. > OUTPUTSח Digital communication, transformer isolated (78.5 kbaud). Calibrated 0 to 4095 digital corresponds to 0 to full scale. POWER CONSUMPTIONDCU with toxic gas sensor/transmitter: 95 ma maximum. וField addressableUnique patented fault isolation ՕUtilizes state-of-the-art communication technology Pass through communication circuitry on power loss ՕTen bit signal resolution capability Two alarm setpoints ՕNon-volatile memory for logging of alarm and cali-bration eventsNon-intrusive one person calibration ՕLED for calibration, fault and alarm status annuncia-tionEMI hardened ՕPluggable screw terminal connectors Compatible with Eagle Quantum Premier and EagleQuantum systems. DCU with transmitter and catalytic combustible gassensor: 180 ma maximum during normal operation, 500 ma during startup. TEMPERATURE RANGE՗ Operating:40ְF to +167F (Ж40C to +75аC). Storage:67ְF to +185F (Ж55C to +85аC). > 2.1 Detector Electronics Corporation 2003 8/0390-1118 size="-1">

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SHIPPING WEIGHT Aluminum:6 lb (2.7 kg) Stainless Steel:10 lb (4.5 kg). DIMENSIONSח CERTIFICATION See Figure 1. FM / CSA:Class I, Div. 1, Groups B, C, D.Class I, Zone 1, Group IIC. Class I, Div. 2, Groups A, B, C, D (T4A). Class I, Zone 2, Group IIC (T4). Class II/III, Div. 1 & 2 (for use with Model STB). NEMA/Type 4X (for use with Model STB).CENELEC/CE:ATEX/EMC Directive Compliant.0539 II 2 GEEx d IIC T4-T6 DEMKO 02 ATEX 131321X T6 (Tamb = ז55C to +50аC). T5 (Tamb = 55ְC to +65C). T4 (Tamb = Ж55C to +75аC). IP66.Special Conditions for Safe Use (X): The device has an ambient temperature rating...

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IMPORTANT EQ2200DCU DIGITAL COMMUNICATION UNIT USED WITH POINTWATCH Insulate the shields to prevent shorting to the device housing or to any other conductor. Attach the communication module to the standoffs asshown in Figure 4. Connect the ribbon cable from the terminal wiring board to the communication module.Set the address for the device (see AddressabilityӔ onpage 3).Check the wiring to ensure proper connections, thenpour the conduit seals and allow them to dry (if conduit is being used). Determine the best mounting locations for the detectors. Whenever practical, detectors should be placed...

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COMMUNICATION MODULESWITCHES ON SAME SIDE(RIGHT)TRANSMITTER BOARDTERMINAL WIRING BOARD > COMMUNICATION MODULESWITCHES ON OPPOSITE SIDES(WRONG)TRANSMITTER BOARDTERMINAL WIRING BOARD > SENSOR POWERCOM 2COM SHIELDCOM 1 AB AB TERMINAL WIRING BOARD >

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Screw the transmitter board to the standoffs as shown inFigure 8. Connect the sensor plug to the transmitter board.Attach the communication module to the standoffsmounted on the transmitter board. Connect the ribbon cable from the terminal wiring board to the communica- tion module.Set the address for the device (see AddressabilityӔ onpage 3). Assembly and Wiring Procedure Connect the external wiring to the appropriate terminalson the DCU terminal wiring board. See Figure 9. IMPORTANT Insulate the shields to prevent shorting to the device housing or to any other conductor. Attach the sensor to...

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