Troubleshooting of Pro face GP Series

Troubleshooting and Maintenance Guide for Pro face GP-2400/2500/2600 Series

In industrial automation sites, human-machine interface (HMI) is the core bridge between operators and control systems. The Pro face GP-2400, GP-2500, and GP-2600 series touch screens have been widely used in various production lines and equipment monitoring systems due to their stable performance, rich interfaces (Ethernet, CF cards, sound output, extended serial ports), and high reliability. However, as the equipment ages or the on-site environment changes, engineers often face a series of typical faults such as no display, communication interruption, unresponsive touch, backlight burning, and clock loss.

This article combines the technical manual and on-site maintenance experience of GP-2400/2500/2600 series to systematically sort out the common fault phenomena, root causes, diagnostic steps, and solutions of this series HMI, and provide preventive maintenance suggestions. Whether you are debugging an old production line or planning to replace spare parts, this article will become a practical portable guide.

Power and hardware installation failure: No display when turned on

1.1 Phenomenon Description

After connecting the power, the GP screen does not light up at all, the status LED does not light up or displays orange, or the screen lights up and immediately goes out.

1.2 Troubleshooting steps

Step 1: Check if the power input meets the model requirements

GP2500-TC11/GP2600-TC11 are AC power supply models: rated voltage AC100V (range AC85~132V) or AC85~265V (Revision 3 and above).

GP2400-TC41-24V、GP2500-LG41-24V、GP2500-SC41-24V、GP2500-TC41-24V、GP2600-TC41-24V  DC24V power supply model: allowable range DC19.2V~28.8V.

Be sure to use a multimeter to measure the input terminal voltage. Exceeding the allowable range may cause damage to the internal power board or protective action.

Step 2: Check the power terminal and fuse

The power terminals are located on the back of the GP and labeled as L, N (AC type) or "+", "-" (DC type). Confirm that the screws have been tightened with a torque of 0.5~0.6 N · m.

Some DC models do not have fuses inside, so it is necessary to check whether the external power supply circuit is short circuited or overloaded.

Step 3: Observe the color of the status LED

Green light constantly on: normal.

Orange: Backlight burnt out or GP internal malfunction (see backlight replacement section later for details).

Not lit: No power input or damaged power board.

Step 4: Forcefully enter offline mode for verification

Within 10 seconds after booting up, touch the top left corner of the screen (hidden switch) to enter the offline (OFFLINE) mode. If you can enter the offline menu but there is no screen in the running mode, it may be due to a damaged project file or a blank startup screen.

1.3 Typical Solutions

Voltage mismatch: Replace the power supply with one that meets the specifications or use a regulated power supply.

Backlight burning: Refer to section 5 for replacing the backlight. Attention: The touch screen still works after the backlight is burned out, which poses a risk of misoperation. The "Disable touch screen after backlight burning out" function should be enabled (enabled in initialization settings → touch screen settings).

Damaged power board: requires repair or replacement of the entire machine.

Communication failure: GP and PLC cannot exchange data

Communication failure is one of the most common alarms on site, and GP screens usually display "PLC COM. ERROR" and error codes such as 02: FD, 02: FE, 02: FC, etc.

2.1 Error Code Quick Reference Table

Solution to Error Code Meaning

02: FC communication parameters do not match (baud rate, data bits, stop bits, parity check). Check if the SET UP SIO settings of GP are completely consistent with the PLC programming port settings. Check the data format sent by the host when using Memory Link.

02: FE PLC does not respond. Check if the PLC is powered on; Confirm that the wiring is correct; Adjust the power on sequence - power on the PLC first, wait for 2-3 seconds, and then power on the GP.

02: FD receiving data errors are usually caused by communication cables being disconnected or strongly interfered with during operation. Check the cable connection, use shielded twisted pair, and ensure that the FG grounding resistance is ≤ 100 Ω.

02: F9 GP station number repetition (multi link n: 1 mode) When multiple GPs are connected to the same PLC, the STATION NO. (0~15) of each GP must be unique. Check the station number settings of all GPs.

The FB tag address is out of range. In Memory Link mode, the system data area address must be within the range of 0 to 2047; Or if the address range of the PLC is too small, the label allocation needs to be modified.

2.2 Hardware Connection Check

The serial port of GP-2400/2500/2600 is D-sub 25 pin (female socket), supporting RS-232C and RS-422. Definition of key pins:

RS-232C: 2-pin (SD), 3-pin (RD), and 7-pin (SG) must be connected; 4. Short circuit control lines such as 5, 6, and 8 as needed.

RS-422: Use 9 (TRMX), 10 (RDA), 11 (SDA), 15 (SDB), 16 (RDB), 18 (CSB) and 19 (ERB) short circuits, 21 (CSA) and 22 (ERA) short circuits, and add a 100 Ω terminal resistor between RDA and RDB.