SIGMATEK TAE1941 Display Unit Replacement and Troubleshooting

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)