SIGMATEK TAE1941 Display Unit Replacement and Troubleshooting



SIGMATEK TAE1941 Touch Display Unit Replacement and Troubleshooting Guide

In the field of industrial automation, updating and upgrading human-machine interfaces (HMI) and display terminals are common tasks for equipment maintenance and upgrading. When the original display unit is discontinued, has insufficient resolution, or cannot meet new visualization requirements, it is crucial to choose a compatible, easy to install, and reliable alternative product. SIGMATEK TAE 1941, as a 19 inch SXGA touch display unit, is an ideal choice for replacing old display terminals due to its high resolution, LED backlight, HMI Link G2 remote connection capability, and design that adapts to harsh industrial environments. This article will delve into the replacement selection, installation and debugging, troubleshooting, and maintenance points of TAE 1941, providing engineers with a practical technical guide.

Overview of Technical Characteristics of TAE 1941

TAE 1941 is a 19 inch TFT color display unit with a resolution of SXGA 1280 x 1024 pixels, a color depth of 24 bits (16777216 colors), a typical brightness of 300 cd/m ², and a typical contrast ratio of 2000:1. Its display angle is excellent, with a left to right and up to down angle of 89 degrees. The backlight adopts LED, and after running for 50000 hours at an ambient temperature of 25 ° C, the brightness decays to 50% of the original value. The touch screen adopts an analog resistive glass touch panel with an effective area of 376.3 x 301.1mm, serving as the input medium for process data and parameters.

In terms of interfaces, TAE 1941 provides one USB 2.0 Type-A (X5) on the front panel and one USB 2.0 Type-A (X4) on the back panel. The core communication interface is HMI Remote IN (HMI Link G2), using RJ45 connectors. The power supply voltage is+24V DC (+18-30V DC), with a typical current consumption of 1.45A (at 24V) and a maximum of 2A. The external dimensions are 462 x 360 x 57mm, and the weight including the installation bracket is about 7kg. In terms of environmental adaptability, the working temperature is 0 to+50 ° C, the storage temperature is -20 to+60 ° C, and the humidity is 10-90% without condensation. EMC complies with EN 61000-6-2 (industrial zone immunity) and EN 61000-6-4 (noise emission). Vibration resistance complies with EN 60068-2-6, 9-200Hz amplitude 3.5mm/1g. The impact resistance complies with EN 60068-2-27, 15g (150m/s ²), lasting for 11ms. The protection level complies with EN 60529: front panel IP54, cover plate IP20. Product code 12-200-1941, hardware version 1. x.

Replacement selection and compatibility evaluation

When deciding to replace the existing display unit with TAE 1941, engineers need to evaluate the following aspects:

1. HMI Link G2 compatibility check

This is the most crucial step in replacement selection. TAE 1941 is a pure display terminal that does not come with a processor and must be connected to the PC through HMI Link G2. The PC side needs to be equipped with SIGMATEK second-generation HMI Link (G2) module, which processes display and USB signals and transmits them to the terminal through standard Ethernet cables (CAT-5e or CAT-6). Therefore, it is necessary to confirm whether the existing control system supports HMI Link G2 before replacement.

It should be noted that the first and second generations of HMI Link devices are incompatible, and G2 devices can only be used in conjunction with remote terminals of the same system family. If the original system uses the first generation HMI Link, it cannot be directly replaced with TAE 1941, and the HMI Link module on the PC side needs to be synchronously upgraded. In addition, if the resolution of the replaced display terminal is different from the original device, the PC must be restarted after replacing the device during operation in order for the system to correctly recognize and initialize the new device.

2. Power supply and power demand assessment

TAE 1941 requires an independent+24V DC power supply, with a typical current of 1.45A and a maximum of 2A. The power supply is connected through the X1 interface (4-pin Phoenix RM 3.5) on the rear panel. When replacing, it is necessary to confirm whether there is sufficient 24V power capacity inside the control cabinet. When used for internal capacitor charging, power consumption may increase in microseconds, depending on the input voltage and power impedance. Therefore, it is recommended that the power supply has a certain margin.

3. Evaluation of mechanical dimensions and installation methods

The external dimensions of TAE 1941 are 462 x 360 x 57mm (height x width x depth), and the installation dimensions are 422 x 320mm. When replacing, it is necessary to confirm whether the original control cabinet openings match. The installation bracket is included in the delivery scope. If there is a slight difference in the original hole size, it may be necessary to reprocess or use an adapter plate.

4. Environmental and chemical tolerance assessment

Confirm that the working temperature is within the range of 0-50 ° C and the humidity is not condensing. Touchscreens are resistant to various chemicals, including coal tar/toluene, trichloroethylene, acetone, alcohol, gasoline, engine oil, ammonia, glass cleaner, mayonnaise, tomato sauce, wine, salad oil, vinegar, etc., and have no visual impact. However, the ASA casing still needs to avoid contact with highly corrosive chemicals during replacement installation.

Mechanical installation and grounding specifications

1. Mechanical installation

TAE 1941 adopts a control cabinet installation method, and the installation bracket is included in the delivery scope. During installation, ensure that the panel opening size matches the installation size (422 x 320mm) and use matching screws to secure it. During the installation process, attention should be paid to avoiding excessive mechanical stress on the touch screen to prevent damage to the glass panel.

2. Grounding connection

Grounding is the key to ensuring the fault free operation of TAE 1941. The terminals must be grounded through the installation or provided connection points on the control cabinet. A low impedance grounding connection must be established to ensure fault free operation. The grounding connection should have the maximum cross-section and the largest possible electrical surface. Any noise signal that reaches the terminal through an external cable must be filtered out through a grounding connection. High frequency noise can also be dissipated through large electrical surfaces (skin effect).

HMI Link G2 Wiring Specification

The wiring quality of HMI Link G2 directly affects the stability of display and USB signal transmission, and is a crucial aspect that requires special attention in replacement engineering.

1. Cable selection

For HMI Link G2 lines, CAT5e or CAT6 cables with shielded RJ45 connectors must be used. The cable shielding layer must be grounded at both ends to prevent noise signals from reaching electronic devices and affecting their functionality.

2. Cable specifications and length limitations

RJ45 cables must be wired 1:1 according to the EIA568A standard. Self made cables must be tested for compliance with the limit values corresponding to the cable category (CAT5e/CAT6, etc.). For CAT5e cables, the total allowable length is limited to 90 meters. To utilize the HMI Link system with a maximum length of 100 meters, at least CAT6 cables are required.

3. Parallel wiring in cable bundles

To ensure proper functionality, it is necessary to ensure that cables do not run parallel for long distances within the cable bundle. This is particularly suitable for fast data cables such as Ethernet, VARAN, and HMI Link. It is recommended to use cables that are equal to or better than the CAT6A standard. When multiple HMI Link cables are laid in parallel, the maximum parallel wiring length limit is as follows: CAT5e/CAT6 can have up to 6 cables within a distance of 30 meters, up to 4 cables within 50 meters, up to 2 cables within 70 meters, and up to 1 cable within 100 meters; CAT6a/CAT7 can have a maximum of 6 pieces within distances of 30 meters, 50 meters, 70 meters, and 100 meters. It is necessary to monitor the crosstalk between data lines and the interference caused by it.

Interface layout and status diagnosis

1. Front panel interface

X5 is a USB 2.0 Type-A interface with pin definitions: 1-+5V, 2-D0-, 3-D0+, 4-GND. Used for connecting USB devices.

2. Status LED diagnosis

The front panel of TAE 1941 is equipped with red and green status LEDs for quick diagnosis of system status:

LED1 is always on in red and LED2 is off in green: there is no HMI Link connection between the PC and the terminal. Check the HMI Link cable.

LED1 flashes red, LED2 turns green off: HMI Link connection between PC and terminal is available, but there is no video signal. Check the display port cable.

LED1 is always red and LED2 is always green: HMI Link connection is available, video signal is available, but there is no USB signal. Check the HMI Link connection.

LED1 red off, LED2 green constantly on: the system is ready and running normally.

Mastering the meanings of these LED states can quickly locate problems during replacement, debugging, and troubleshooting.

3. Rear panel interface

X1 power supply: 4-pin Phoenix RM 3.5, pins 1 and 2 are+24V, pins 3 and 4 are GND.

X2 HMI Remote IN: HMI Link G2, RJ45 interface. Pin definition: 1- HMI_P0，2-HMI_NO，3-HMI_P1，4-HMI_P2，5-HMI_N2，6-HMI_N1，7-HMI_P3，8-HMI_N3。

X3 service interface: 3.5mm 4-pin socket, compliant with IEC 60603-11. Pin 1-GND, 2-TxD, 3-RxD, 4- unused. For service purposes only, special cables ordered by SIGMATEK must be used. Using other cables may cause malfunctions and damage.

X4 USB Type-A interface.

4. Applicable connectors

X1 uses Phoenix Contact FK-MCP 1.5/4-ST-3.5 (not included in the delivery scope). X2 uses RJ45 connector plug, at least CAT5e 8-pin (not included in the delivery scope). Wire stripping length 10mm, rigid conductor cross-section 0.2-1.5mm ², flexible conductor cross-section 0.2-1.5mm ², AWG 24-16.

Common troubleshooting

1. The display terminal has no display (LED1 is always red and on, LED2 is green and off)

Firstly, check if the HMI Link cable is securely connected. Confirm that the HMI Link G2 module on the PC is powered on and functioning properly. Check if the cable meets CAT5e or CAT6 specifications and if the shielding layer is grounded at both ends. If the cable length exceeds 90 meters (CAT5e), it needs to be replaced with CAT6 or the distance shortened.

2. No video signal (LED1 flashing red, LED2 turning green)

The HMI Link connection has been established, but the video signal has not yet arrived. Check if the PC display port cable is connected correctly. Confirm that the PC graphics card or display output is normal. If a display terminal with different resolutions is replaced during operation, the PC needs to be restarted to correctly recognize the new device.

3. No USB signal (LED1 red constantly on, LED2 green constantly on)

The HMI Link connection and video signal are both normal, but the USB signal is missing. Check if the USB signal cable pair of HMI Link cable is intact. Confirm that the USB function of the HMI Link G2 module on the PC is enabled. Check if the USB device complies with the specifications.

4. Abnormal touch function

If the touch is inaccurate or ineffective, the touch screen needs to be recalibrated. Calibration data is stored on the PC end, not the display unit. After each replacement of the display unit, it must be recalibrated. If the automatic detection fails, the resolution of 1280 x 1024 needs to be manually set in the PC BIOS or operating system.

5. The display terminal cannot start

Check if the X1 power supply voltage is within the range of+18-30V DC. Measure whether the current consumption exceeds 2A. Check whether the power supply has sufficient power margin to cope with the capacitor charging shock when powered on. Confirm that the polarity of the power supply wiring is correct.

6. ESD interference causes USB device failure

USB devices (keyboards, mice) usually do not come with shielded cables and are susceptible to ESD interference. Before connecting or disconnecting any device, static electricity should be released by touching the control cabinet or grounding terminal to dissipate the static load (generated by clothing/shoes).

Cleaning and maintenance

To extend the service life of TAE 1941, it is necessary to regularly clean the touch screen and housing. Before cleaning, be sure to turn off the terminal power to avoid triggering functions or commands by mistake. Use a soft, damp cloth dipped in antistatic foam, water and mild detergent or alcohol. The cleaning solution should be sprayed on the cloth, not directly on the terminal, to prevent the liquid from entering the electronic components through the ventilation groove. It is strictly prohibited to use abrasive cleaners, chemical solvents, or hard objects to scratch the touch screen. If exposed to toxic or corrosive chemicals, it should be carefully cleaned immediately to prevent corrosion. It is recommended to operate the touch screen with your fingers to extend its lifespan. When disposing of products, it is necessary to comply with local regulations.