UniOP ePAD05/06 Human Computer Interface

UniOP ePAD05 and ePAD06 Compact Human Computer Interface: Technical Depth and Engineering Practice

In the field of industrial automation, human-machine interfaces do not always require color touch screens. A large number of small and medium-sized equipment, such as packaging machines, injection molding machine auxiliary equipment, environmental testing chambers, and simple tooling platforms, place greater emphasis on the reliability of physical buttons, the coverage of communication protocols, and the overall economy of the machine. After successfully launching the ePAD03/04 series, UniOP further launched two products, ePAD05 and ePAD06. They significantly enhance operational capabilities while maintaining the same compact size and monochrome display specifications: 9 programmable function keys (with slide in labels), 10 user LED indicator lights, and provide more complete data traceability functionality (especially ePAD05 equipped with hardware real-time clock and recipe storage). EPAD06 serves as a further cost optimized version, suitable for pure display and control scenarios that do not require timestamps and recipe management. Some models support an extended operating temperature range (suffix -00B6 and -00B7) and can operate stably in harsh environments ranging from -20 ℃ to 60 ℃. This article will comprehensively analyze ePAD05 and ePAD06 from multiple dimensions such as hardware architecture, communication expansion, software functionality, installation size, on-site troubleshooting, and selection and replacement strategies, providing a practical technical reference for engineers who are currently using or planning to introduce this series of HMI.

Product positioning and model comparison

EPAD05 and ePAD06 are officially defined as the "ideal supplements" to ePAD03/04. Compared to ePAD03 (4 function keys, 5 user LEDs), ePAD05/06 has 9 function keys and 10 user LEDs, making it more suitable for operation stations that require frequent triggering of different actions such as start, stop, reset, manual/automatic switching, and parameter increment/decrement. The two share the same casing, display screen, and basic electrical parameters, with the core difference being the internal functional modules:

EPAD05: Full featured version. Equipped with hardware real-time clock (RTC, backed up with CR2430 lithium battery), 16KB recipe memory, 1024 alarm capacity, 256 event list, dual driver communication capability, UniNET network support (Server/Client mode).

EPAD06: Economic version. No hardware RTC, no recipe memory, reduced alarm capacity to 256, no event list, no dual driver communication (single driver only), UniNET only supports client mode.

From the suffix of the ordered model:

-0046: Standard operating temperature 0~+50 ℃

-00B6: Extended working temperature 0~+60 ℃

-00B7: Wide temperature version, working temperature -20~+60 ℃, storage temperature -20~+70 ℃

When selecting, engineers must choose ePAD05 if they need to record the exact time of operational events (such as for quality traceability or fault analysis), or if they need to store multiple sets of formula parameters, or if they need to connect two different protocol PLCs simultaneously. If only used for real-time data display and simple settings of a single PLC, and without timestamp requirements, ePAD06 can further reduce procurement costs.

Analysis of Hardware Technical Parameters

2.1 Display and Interaction

Both products use monochrome LCD with a graphic resolution of 120 × 32 pixels and an active display area of 70 × 21 mm, capable of presenting text of 4 lines × 20 characters. Supports downloadable fonts and scalable fonts, allowing display of characters in different languages and sizes, and supports 256 user-defined characters. The contrast is adjusted through software, and the LED backlight ensures readability in dark environments.

The configuration of physical buttons and indicator lights is a major highlight of ePAD05/06:

9 user programmable function keys: Each function key is equipped with a slide in label slot, allowing users to print paper labels for insertion and intuitively define key functions (such as "start", "stop", "parameter settings", "manual", etc.).

10 system keys: including directional keys (up/down/left/right), numerical input keys, confirm keys, exit keys, etc.

10 user programmable LED indicator lights: can be mapped to bit variables in the PLC, used to display motor status, valve in place, fault alarms, etc.

Four system LEDs: typically used to indicate power, communication activity, alarm status, etc.

A total of 19 physical buttons and 14 LEDs enable operators to quickly complete most control tasks without relying on screen menus, and are equally reliable in gloved or dimly lit environments.

2.2 Electrical and Environmental Parameters

Supply voltage: 18~30 VDC (nominal 24V DC)

Maximum power consumption: 0.25 A @ 24 VDC (approximately 6W)

Overcurrent protection: external or internal self recovery fuse (requires cooperation with overcurrent protection device)

Weight: Approximately 1 kg

Protection level: IP65 front panel (dustproof and water-resistant)

Working temperature: Depending on the suffix, covering -20 ℃~+60 ℃

Storage temperature: -20 ℃~+70 ℃

Humidity: 5~85% RH, no condensation

Electromagnetic compatibility: Compliant with EN 61000-6-4 (radiated interference) and EN 61000-6-2 (immunity), suitable for industrial environments.

2.3 Mechanical dimensions and openings

Same as ePAD03/04:

Panel size (width x height): 149 x 109 mm (5.86 "x 4.29")

Hole size (width x height): 136 x 96 mm (5.35 "x 3.78")

Installation depth: 53 mm (2.08 ")

Maximum panel thickness: 5 mm (0.19 ")

This standard size allows ePAD05/06 to seamlessly replace ePAD03/04 or MD00 series without the need to modify the control cabinet door panel.

Communication and networking capabilities

3.1 Built in PLC port

Both products offer a multi protocol PLC port that can be configured through software as RS-232, RS-422, or RS-485. This port supports over 130 types of industrial communication drivers, covering mainstream brands of PLCs such as Siemens, Rockwell, Mitsubishi, Omron, Schneider, Delta, as well as various frequency converters and instruments. Typical applications:

RS-232: point-to-point short distance connection (such as with Siemens S7-200 PPI, Mitsubishi FX programming port).

RS-485: Multi node bus, suitable for Modbus RTU master or multiple slave devices (such as multiple frequency converters).

RS-422: Full duplex long-distance communication (up to about 1200 meters), suitable for noisy environments.

3.2 Dual driver communication capability

EPAD05 supports dual driver communication, which means it can run two different protocols simultaneously. For example, the PLC port is connected to a temperature controller using Modbus RTU protocol, while communicating with the upper computer SCADA system via TCP/IP through the Ethernet module on the Aux port. EPAD06 does not have this capability and can only use one protocol simultaneously.

3.3 Optional modules and fieldbus

Through the Aux port (auxiliary port), users can insert the following optional modules:

Fieldbus modules: Profibus DP, DeviceNet, CANopen, Interbus

Ethernet module: Supports TCP/IP and can achieve:

Connect PLCs with Ethernet interfaces (such as Siemens S7-1200, Rockwell CompactLogix)

Download/upload projects from UniOP Designer via Ethernet

Send alarm, event, and recipe data to the upper computer

Building a UniNET Network

3.4 UniNET Network

EPAD05: Supports UniNET's Server and Client modes. Can serve as a data server, providing its internal variables to other UniOP HMIs in the network; It can also serve as a client to read data from other HMIs or UniNET OPC Server.

EPAD06: Only supports Client mode, can only passively obtain data, and cannot be provided externally.

Deep analysis of software functions

4.1 Alarm and Event Management

EPAD05: Up to 1024 alarms, 256 historical event lists (with timestamps, dependent on hardware RTC). Alarm information can be associated with bit addresses, support priority and confirmation methods, and can be printed or output through Ethernet.

EPAD06: Up to 256 alarms, no event list function.

For pharmaceutical, food, or automotive parts industries that require traceability of operational records (such as who modified the set values at what point), ePAD05's 256 event list is an important tool for compliance.

4.2 Formula Storage

EPAD05: Built in 16KB non-volatile formula storage, which can be divided into multiple formula tables, each of which stores a set of process parameters (such as the 5-stage temperature, pressure, and time of the injection molding machine). The operator selects the recipe number through the keyboard and uploads it to the PLC or saves the current value to the recipe with one click.

EPAD06: No recipe memory.

4.3 Macro Editor and Dynamic Graphics

The powerful keyboard macro editor allows users to write script logic, such as:

When the temperature exceeds the threshold, the screen will automatically switch and the LED will flash;

Long press the function key for 3 seconds to perform a special operation;

Write the calculation results of two variables into the PLC.

Dynamic graphical objects (bar charts, rotating parts, moving bars) can change in real-time based on variable values, enhancing operational intuitiveness.

4.4 Password Protection

Eight level password protection can finely control the different permissions of operators, technicians, engineers, and administrators. Support hiding sensitive images, locking specific function keys, or limiting parameter modification range.

4.5 Multilingual and Scalable Fonts

The application can have multiple built-in languages and switch between them at runtime through system bits or buttons. All text can be exported in Unicode format for easy translation. Scalable fonts ensure clear display of different glyph types (such as Chinese, Korean, Cyrillic letters) within a limited area of 120 × 32 pixels.

4.6 Programming and Download

Use UniOP Designer software (version 6 or higher) for configuration. Download speed:

EPAD05: 9600~38400 bps (adjustable)

EPAD06: 9600 bps (fixed)

Engineering points for replacing ePAD03/04 or MD00 series

5.1 Upgrading from ePAD03/04 to ePAD05/06

If ePAD03 (4 function keys) was originally used but on-site operation requirements increase, more shortcut keys are needed, which can be smoothly migrated to ePAD05/06:

Mechanical compatibility: The opening size is exactly the same, and can be replaced directly.

Electrical compatibility: The definitions of power supply and communication wiring are consistent.

Engineering migration: Change the target device to ePAD05/06 in Designer, while retaining the original screen and variable definitions. However, it should be noted that ePAD05/06 has a larger number of function keys and requires reassignment of key actions; The newly added recipe and event list functions in ePAD05 can be enabled as needed.

Cost considerations: The price of ePAD05 is slightly higher than that of ePAD03, but the functional density has been significantly increased.

5.2 Replacement from MD00 series

EPAD05/06 is the ideal upgrade path for MD00 series text displays. Notes:

Communication compatibility: Most of the drivers supported by MD00 are covered, but it needs to be confirmed whether there is a 20 mA current loop interface (ePAD series does not support current loops and requires an additional converter).

Engineering reconstruction: MD00 uses outdated software, and the project needs to be reconfigured in Designer. You can refer to the original screen layout and variable addresses for quick reconstruction, which usually takes 2-3 days to complete.

Function gain: ePAD05/06 has added capabilities such as graphic display, bar chart, scalable fonts, macro editing, password protection, etc. After replacement, it can significantly improve the operating experience.

Common troubleshooting and on-site maintenance

Based on the hardware structure of ePAD05/06 and years of on-site experience, the following are six types of high-frequency faults and their handling processes. Be sure to disconnect the 24V power supply before operation.

Fault 1: No display when powered on, power LED does not light up

Possible reasons:

The 24V power supply is not connected or the polarity is reversed.

The overcurrent protection device (fuse) has blown.

The internal DC-DC circuit is damaged.

Troubleshooting steps:

Measure the power terminal voltage (18-30V) with a multimeter.

Check the external fuse or circuit breaker.

Disconnect all peripherals (PLC lines, modules) and supply power to HMI separately. If restored, a short circuit in the external device will cause protection action.

If there is still no response, repair or replace.

Fault 2: No response or individual keys malfunction

Possible reasons:

Slide the label paper into the slot of the button.

The keyboard membrane may age or become contaminated after prolonged use.

The system has entered a password lock state.

Troubleshooting steps:

Take out the label paper and test the physical feel of the buttons.

Enter the system diagnostic mode (press and hold specific function keys when powering on, refer to the manual), and test the keyboard matrix.

Clean the edges of the buttons with anhydrous alcohol.

Check password protection settings and confirm that they are not locked.

Fault 3: Communication interruption or data jump

Possible reasons:

The communication parameters (baud rate, data bits, checksum) do not match the PLC.

The RS-485 bus is not connected to a terminal resistor or the A/B lines are reversed.

Incorrect physical interface was used (e.g. selecting RS-422 but actually wiring RS-485).

The optional module has poor contact.

Troubleshooting steps:

Check the driver and parameters in Designer.

Point to point short distance testing (<10 meters) to eliminate cables and interference.

For RS-485, confirm that A (+) is connected to A and B (-) is connected to B, and check the terminal resistance (120 Ω usually only needs to be connected at both ends).

Re plug and unplug the optional module, clean the golden finger.

Fault 4: Inaccurate real-time clock timing or power-off reset (only ePAD05)

Possible reasons:

The internal CR2430 lithium battery is fully charged (with a typical lifespan of 3-5 years).

Replacement steps:

Open the back cover after power failure (pay attention to electrostatic protection).

Find the battery holder and remove the old battery.

Install the CR2430 lithium battery of the same model (with the positive electrode facing upwards) and ensure that the battery operates within the required temperature range (industrial grade batteries are required for wide temperature models).

Power on again and enter the system menu to calibrate the time.

If it is still lost, check the battery socket solder joints or nearby circuits.

Fault 5: Abnormal screen contrast or incomplete display

Possible reasons:

Improper software contrast setting.

The LCD cable is loose or oxidized.

LCD aging (usually occurring after more than 5 years).

Troubleshooting steps:

Adjust the contrast in the system menu or user screen (if open).

Disassemble and inspect the LCD cable plug, re plug and clean the gold finger.

If there are missing lines or a blurred screen, it is usually necessary to replace the display screen components.

Fault 6: Unable to program or transmit data through Ethernet module

Possible reasons:

The Ethernet module did not obtain a valid IP (DHCP not enabled or no static IP).

Designer is incompatible with HMI firmware version.

The firewall or switch is blocking the communication port (default 1024).

The wrong type of Ethernet cable was used (direct vs crossover).

Troubleshooting steps:

View module status and IP address on the HMI system information page.

Use the ping command to test connectivity.

Specify the correct IP in the Designer transport settings.

Try using a crossover cable to directly connect the PC and HMI (excluding switch issues).

Update HMI firmware to the latest version.

Upgrade and Replace Paths

When ePAD05/06 cannot meet the requirements of new projects or needs to be migrated to higher performance platforms, the following paths can be considered:

Path 1: Keep ePAD05 and add an extension module

If you need to connect to Profibus DP or Ethernet, simply purchase the corresponding optional module and insert it into the Aux port without replacing the main body. This is the lowest cost upgrade method.

Path 2: Upgrade to eTOP series

If you need color display, larger screens (5.7 inches or more), touch functionality, or faster processors, you can choose the UniOP eTOP series (such as eTOP 05, eTOP 10). Engineering files can be converted to target devices in Designer, but resolution and control layout need to be re adapted.

Path 3: Cross brand replacement with domestic text screen

When procurement channels are limited or cost pressures are high, domestic text displays (such as Xinjie OP320 and Weikong LEVI) can be used to replace ePAD06. However, it should be noted that:

There are few domestic screen communication drivers, which may prevent connection to non mainstream PLCs.

The number of physical buttons is usually less than 9 (usually 4-6), and there is a significant change in operating habits.

The project needs to be completely rewritten, resulting in high migration costs.