Description
1. Product Overview
Allen‑Bradley 2706‑D21J2 is a dedicated industrial text information display terminal of Rockwell Automation 2706‑series DL5 Dataliner. It is a classic human‑machine interaction device for legacy industrial control systems, widely used with full‑range AB PLCs, automated production lines, complete process equipment and power unit control systems. This terminal is mainly used for on‑site industrial equipment status display, process information pop‑ups, fault text prompts and visual presentation of operating parameters. It serves as the simplest human‑machine interaction solution for small‑and‑medium automated equipment. It can receive text commands issued by the main control system in real time and clearly display equipment operating conditions, alarm messages, process status and operation prompts.
Equipped with a VFD (Vacuum Fluorescent Display) screen, the 2706‑D21J2 delivers high brightness, high definition, wide viewing angle, backlight‑interference resistance and high‑brightness performance at low temperature, suitable for industrial sites with dim workshop lighting, dust and fluctuating temperature and humidity. Built‑in 2KB EEPROM memory unit permanently saves preset text information without battery backup, and data will not be lost upon power‑off. It supports dual‑mode communication, and the parallel / serial communication mode can be freely switched via DIP switches to meet diversified networking requirements of legacy industrial control systems. Featuring compact structure, ultra‑low power consumption, stable operation and low failure rate, it is a core model for non‑destructive on‑site replacement of aging human‑machine terminals on old production lines suffering from dark screen, communication failure and information display malfunction.
2. Functional Features
Dual‑line High‑definition Text Display with Excellent Industrial Visibility
Adopting classic dual‑line text display architecture, each line shows 16 standard characters with 32 characters displayed simultaneously. It can fully present text information such as equipment operating status, fault codes, alarm prompts, process conditions, start‑stop hints and parameter abnormalities. Fitted with industrial‑grade VFD screen, compared with ordinary LCD screens, it features high brightness, no ghost image, wide viewing angle, no screen distortion at cold startup and clear readability under strong light, satisfying all‑weather production observation requirements in factories.
Permanent Power‑off Storage without Battery Backup
Built‑in 2KB large‑capacity EEPROM storage area supports storing up to 94 blocks of 16‑character messages. Users can freely edit, store and call various custom process texts, fault prompts and status statements. Stored data is solidified and preserved without backup battery. All preset information remains intact after power‑off, restart or shutdown, completely eliminating data erasure and program loss caused by battery failure in traditional terminals. It requires zero daily maintenance with extremely high reliability.
Switchable Dual‑port Communication with Powerful Networking Compatibility
On‑board dual communication hardware ports allow free switching between parallel communication and serial communication via DIP switches. Two ports cannot run simultaneously but can be flexibly switched on demand, perfectly matching legacy AB PLC control systems of different generations and protocols. Supporting standard RS‑232 serial communication, it can be quickly connected to main‑control PLC, upper‑level programming devices and on‑site industrial‑control networks, delivering stable data transmission and fast command response, and is compatible with most traditional complete automated equipment.
Light‑weight Human‑machine Interaction to Simplify On‑site Operation & Maintenance
Focusing on simplified on‑site industrial human‑machine interaction, it requires no complex configuration programming. It directly receives text commands from the main control system and refreshes equipment operating status, fault alarms and process prompts in real time. Field maintenance personnel can intuitively judge fault types, operating conditions and abnormal points through the terminal without upper computers, greatly improving on‑site troubleshooting efficiency and operation‑maintenance convenience.
Industrial‑grade Ultra‑low‑power Design for Long‑term Continuous Operation
The complete machine adopts low‑power circuit architecture compatible with two common industrial power supply specifications: 12 VDC and 24 VDC. It features small operating current and extremely low heat generation with no overheating, screen degradation or circuit aging during long‑time operation. Having passed strict industrial aging, vibration and EMC tests, it is anti‑interference, vibration‑resistant and tolerant to temperature‑humidity fluctuation. It supports 7×24‑hour non‑stop continuous operation and adapts to long‑term continuous‑production conditions of production lines.
Compact Embedded Structure for Retrofit of Legacy Equipment
With small dimensions and panel‑mount embedded installation, it fits reserved mounting positions on traditional control cabinets and complete‑equipment panels without cabinet modification. Free of complex keys and redundant functions, it boasts minimal structure and low failure rate. It is suitable for technical retrofit and replacement upgrade of legacy automated equipment, and can directly replace damaged, invalid or abnormally‑displayed old terminals of the same series with convenient retrofit and low cost.
3. Technical Parameters
Basic Specifications
Product Model: 2706‑D21J2；Brand & Manufacturer: Allen‑Bradley (Rockwell Automation)；Product Series: 2706 Series Dataliner DL5 Industrial Text Display Terminal；Product Type: Industrial HMI Text Display Terminal；Core Positioning: On‑site human‑machine interaction unit for equipment status display, fault text prompt and process information visualization of industrial control systems；Core Features: VFD high‑brightness display, dual‑line text output, EEPROM power‑off storage, switchable dual‑mode communication, ultra‑low power consumption, wide‑voltage power supply, non‑destructive replacement for legacy systems.
Display and Storage Parameters
Display Screen: Industrial Vacuum Fluorescent Display (VFD)；Display Format: Dual‑line display, 16 characters per line, total 32 characters；Storage Medium: Built‑in EEPROM non‑volatile memory；Storage Capacity: 2 KB；Message Storage Capacity: Supports 94 blocks of 16‑character messages, custom texts saved permanently；Display Characteristics: Wide viewing angle, high brightness, stable low‑temperature display, ambient‑light interference resistance；Refresh Mode: Real‑time command refresh, synchronous status update.
Communication Parameters
Communication Ports: Switchable dual‑port (Parallel / Serial)；Communication Interface: Standard RS‑232 serial port；Switching Method: Manual mode switching via on‑board DIP switches；Networking Compatibility: Compatible with full‑range legacy AB PLC control systems and old industrial‑control networks；Transmission Characteristics: Low‑latency, high‑stability and anti‑interference data transmission；Operation Mode: Single‑mode independent operation; two ports cannot be enabled simultaneously.
Electrical Operating Parameters
Power Supply: Wide‑voltage adaptation 12 VDC / 24 VDC；Operating Current: 250 mA @12 V, 125 mA @24 V；Inrush Current: Max. 300 mA；Operating Power Consumption: Ultra‑low‑power design for long‑term energy‑saving stable operation；Operation Mode: 7×24‑hour uninterrupted year‑round operation；Anti‑interference Grade: Industrial Class‑A EMC, resistant to workshop electromagnetic crosstalk；Operating Characteristics: Free of screen flicker, garbled data and storage loss.
Environmental and Mechanical Parameters
Operating Temperature: 0℃～+60℃；Storage Temperature: ‑40℃～+85℃；Operating Humidity: 5%～95% non‑condensing；Ingress Protection: Panel‑level industrial dust‑proof and moisture‑proof protection；Installation Mode: Standard panel‑mount embedded installation；Structural Features: Compact body, vibration‑resistant, anti‑aging, no vulnerable components；Applicable Working Conditions: Continuous‑production conditions for light industry, rubber‑plastic industry, packaging industry, production lines and traditional complete industrial‑control equipment.
4. Hardware Configuration and Structural Advantages
VFD Vacuum Fluorescent Display for Superior Industrial Visual Performance
Compared with conventional LCD terminals, VFD screens deliver better industrial adaptability: no black screen under low temperature, clear readability under strong light, no yellowing or brightness degradation after long‑term operation. It adapts to workshop sites with large temperature difference and complex lighting conditions, ensuring maintenance personnel can accurately read equipment status and fault information at any time.
Battery‑free Power‑off Storage for Zero‑maintenance High Reliability
Adopting EEPROM solid‑state storage solution and eliminating traditional battery‑backup storage structure, it fundamentally avoids program loss and text erasure caused by battery aging, liquid leakage and failure. Data is permanently solidified without loss after frequent startup‑shutdown or power‑off, greatly reducing operation‑maintenance workload and failure probability.
Switchable Dual‑mode Communication for Full‑coverage Compatibility with Legacy Systems
Supporting one‑click switching between parallel and serial communication modes, it adapts to old AB PLC systems of different periods and protocols and solves the pain point that traditional single‑communication‑mode terminals are incompatible with old equipment. It features flexible networking and wide adaptability, and can be directly connected to various legacy industrial‑control systems without adapter modules with excellent compatibility.
Minimal Hardware Architecture with Extremely Low Failure Rate
The complete machine has streamlined circuits without complex computing chips or high‑frequency vulnerable parts. It features stable and durable structure, strong vibration resistance and high electromagnetic interference immunity. It rarely suffers from black screen, garbled code or communication interruption in long‑term field operation, and boasts higher stability than ordinary touch‑screen HMIs, suitable for non‑stop production scenarios.
Embedded Compact Design with Strong Retrofit Adaptability
With standard industrial panel mounting dimensions, thin and compact body, it can be embedded into reserved mounting holes of old equipment without drilling, cabinet modification or wiring adjustment. Easy to install and fix, it fits retrofit and upgrade scenarios for various complete automated equipment and control cabinets.
Original‑factory Standardized Design for Non‑destructive On‑site Replacement
Strictly complying with Rockwell original‑factory hardware standards for 2706 series, it is fully interchangeable in dimensions, communication logic, power‑supply specifications and display functions. It can directly replace damaged, aged or abnormally‑displayed old terminals of the same series on‑site. No reprogramming, networking commissioning or system‑program modification is required, and equipment repair can be completed within short downtime.
5. Application Scenarios
Traditional Automated Production‑line Equipment: Widely used in packaging machinery, textile equipment, rubber‑plastic equipment, conveyor production lines and other traditional automated equipment to display equipment operating status, process prompts, fault codes and shutdown reasons and realize simple on‑site human‑machine interaction.
Complete Industrial‑control Cabinet Systems: Used together with AB PLC control systems as local status display units to feed back real‑time process parameter status, equipment abnormal alarms and system operation hints, making up for the lack of on‑site visualization in systems without touch‑screen HMIs.
- Power and Auxiliary Unit Monitoring: Applied in control systems of auxiliary power equipment such as fans, water pumps and heat‑exchange units to display unit start‑stop status, overload faults, operation abnormalities and process linkage hints and guarantee stable operation & maintenance of power equipment.
