GMW IPP 144-40 GS Thermal Printer Troubleshooting Guide



GMW IPP 144-40 GS Thermal Printer Troubleshooting Guide

In the field of industrial automation and process control, although paperless monitoring has become mainstream, on-site printing output is still an important credential for fault tracing, batch recording, and compliance auditing. The IPP 144-40 GS launched by Gossen M ü ller&Weigert (GMW) is a classic industrial standard panel mounted thermal graphic printer. It receives data through RS232 or 20mA current loop (TTY) interface and can print process data, alarm records, statistical reports, and even Windows graphics at a speed of 48 characters/line.

For on-site maintenance engineers in the "search solution" stage, how to quickly determine whether it is a hardware failure, interface setting error, or parameter configuration problem when the printer encounters "communication failure", "printing blank", or "garbled code" is the key to restoring the production line recording function. This article will provide an in-depth analysis of the hardware architecture, interface specifications, menu configuration logic, and common troubleshooting methods of IPP 144-40 GS.

Hardware architecture and security standards

IPP 144-40 GS adopts standard DIN panel installation method (size 144 x 72 x 159mm), with a protection level of IP50. The device supports multiple power supply solutions: 10-19V DC, 19-36V DC, or 85-265V AC (45-65Hz switching power supply).

1. Safety grounding and electrical isolation

Before carrying out any wiring or maintenance operations, it is necessary to ensure that the protective earth (PE) terminal of the equipment is reliably connected. This device complies with the EN 61010-1 standard and is suitable for CAT III (>150V, ≤ 300V) environments. When using a low-voltage DC system, it is recommended to use shielded cables to reduce electromagnetic interference (EMC). It is particularly important to note that when replacing the paper roll during the printing process, if the equipment is powered by AC, there may still be dangerous voltage inside after opening the front cover, and it must be operated by qualified personnel.

2. Interface hardware configuration

There are two physical implementations of the serial interface of the device:

Standard interface I: 9-pin D-Sub socket, supporting RS232, RS422, RS485.

Expansion interface II (only available in version E): 9-pin D-Sub or USB-B interface.

For RS232/RS422/RS485 mode, the S101 dip switch on the motherboard must be turned to the right side; If using 20mA current loop (TTY) mode, dial to the left. The switch is located inside the front panel and can only be seen by loosening the buckle and opening the front cover. Configuration errors can cause complete communication interruption.

Menu configuration and parameter locking

All functional parameters of IPP 144-40 GS, such as baud rate, character set, and print format, are set by entering the menu program through the "MENU/SELECT" and "ENTER" keys on the front panel.

1. Parameter printing and modification process

Enter the menu: Long press the "MENU/SELECT" button for about 3 seconds, and the printer will output "ACTUAL ParameterS? PRESS ENTER".

View current parameters: Press the "ENTER" key, and the printer will print out all current configurations.

Modify parameters: After the prompt "CHANGE VNet?" appears, press and hold the "ENTER" and "SELECT" keys simultaneously for about 4 seconds to enter modification mode. In modification mode, press "ENTER" to accept the current value and jump to the next item, press "SELECT" to switch options.

Save and Exit: Press "ENTER" and "SELECT" simultaneously to end the modification, and the printer will print "END" and permanently save the parameters. If there is no button operation for about 2 minutes, the program will automatically exit without saving any modifications.

2. Jumper B to prevent misoperation

In order to prevent on-site personnel from mistakenly changing parameters, there is a jumper B on the motherboard. The jumper is in a disconnected state when it leaves the factory. If jumper B is short circuited, the "MENU/SELECT" key will be locked, and all parameters cannot be printed or modified. Before making any parameter adjustments, it is necessary to confirm that jumper B has been disconnected.

3. Key communication parameter configuration

In the menu, engineers must strictly match the following parameters according to the settings of the upper computer (PLC or PC):

SET BAUD RATE: Supports 110 to 38400 bps.

SET DATA FORM: 7 bits or 8 bits of data. Note: If using 7 data bits without parity check, the sender must set 2 stop bits.

SET PARTY: Even parity, odd parity, tag, space or no parity.

SET INTERFACE: Optional options include Serial (standard serial port), EMUL.EPS.LQ580 ESC/P2 (compatible with Epson graphic printing), or EMUL.TALLY T2024 (Windows graphic printing).

Common fault diagnosis and troubleshooting steps

When the printer has no output or abnormal output, please follow the following logic to troubleshoot.

1. Print blank or no output at all

Check the paper status: First, observe whether the "ALARM" LED on the front panel is lit, which usually indicates that the paper roll is exhausted or the front cover is not tightly closed. After replacing the paper roll, the LED should turn off.

Check communication status: Confirm if the sending indicator light (TXD) on the upper computer is flashing. Use a multimeter to measure for any data level jumps on the RxD pin (pin 2) of the printer. If there is no signal from the sender, check if the serial port configuration of the upper computer (baud rate, parity check, data bits) is consistent with the printer menu.

Check handshake signal: When the printer buffer (16 kByte) is almost full, the front cover is open, or there is a shortage of paper, the printer will send the XOFF character and pull down the RTS signal. If the upper computer adopts hardware flow control (RTS/CTS), it is necessary to ensure that the RTS signal line is connected correctly (pin 8 corresponds to the upper computer CTS).

2. Blank lines with "no reason" appear

This is a very typical software configuration issue. IPP 144-40 GS supports a maximum of 48 characters per line (standard font). If the text lines sent by the upper computer exceed 48 characters, or there are extra spaces before the line break (CR), the extra parts will be discarded by the printer and may generate additional blank lines. Please check the length of the text sent by the upper computer to ensure that each line does not exceed 48 characters.

3. Menu cannot be printed

If there are no parameters to print after pressing "ENTER", first check if jumper B is short circuited. Secondly, check if the power supply voltage is normal. You can try pressing the "LINE FEED" button to observe if the paper roll is running, in order to determine if the printer is in a crash state. If necessary, press the reset button (102) to reinitialize the printer.

Maintenance and replacement of spare parts

1. Paper roll replacement

Open the front cover, tilt the metal wire rack upwards, and remove the old paper roll.

Insert a new paper roll (80mm wide, maximum outer diameter 40mm, inner diameter 11.5mm), note that the paper roll should rotate clockwise during printing.

Cut the front end of the paper flat and insert it into the bottom of the printer mechanism until the roller automatically rolls in.

Press the "LINE FEED/ENTER" button until the paper is exposed from the cutting edge.

Close the front cover, make sure the buckle is locked, and turn off the "ALARM" light.

2. Key spare parts and accessories

Paper: 80mm wide commercial document grade thermal paper (item number: 49234 86910).

Cable: Siemens PT88 desktop printer (item number: 27866 79461) can be connected through an adapter cable.

Paper Winder (IPP-AW): Used for automatic winding of printing paper. The device must be connected to a protective grounding, and its motor torque has been adjusted by the factory. If the winding force needs to be adjusted, the screw in the side hole can be slightly rotated (clockwise to increase, counterclockwise to decrease).