HMS Airbus X-gateway troubleshooting

HMS Anybus X-gateway Troubleshooting and Configuration Guide

Industrial sites often require the connection of automation equipment from different manufacturers and protocols. The Anybus X-gateway is an intelligent protocol gateway launched by HMS, which integrates two Anybus-S network interface cards and forwards data bidirectionally through a gateway platform. It can realize the interconnection of any two networks such as PROFIBUS, Modbus, EtherNet/IP, PROFINET, CANopen, etc., and supports mixed master/slave configuration.

Although gateway design emphasizes plug and play, in actual operation, communication interruptions, data asynchrony, and loss of slave stations may still occur. This article is based on the core technical information of the Anybus X-gateway user manual, and compiles a systematic troubleshooting and configuration optimization process to help engineers diagnose and restore gateway operation without the need for specialized software, using only terminal simulation tools.

System Architecture and Data Exchange Fundamentals

2.1 Internal Data Flow

The Anybus X-gateway contains two independent network interfaces (called Upper and Lower), each with its own input/output buffer. The gateway periodically copies input data from one side to the output buffer on the other side, and vice versa. Each buffer can support a maximum of 512 bytes, but the actual amount of data that can be exchanged depends on the limitations of the specific network protocol.

Fault prompt: If data is only transmitted in one direction or not updated at all, first check whether the I/O data length configuration of the two interfaces matches, and whether the control word/status word function is enabled (which will occupy additional mapping space).

2.2 Loop I/O and Non Loop Parameter Data

Most fieldbuses distinguish between cyclic I/O data (fast, periodic) and non cyclic parameter data (slow, on-demand access). The X-gateway processes these two types of data separately:

Input I/O data size: The number of bytes of cyclic data sent from the gateway to the network.

Output I/O data size: The number of cyclic data bytes received and forwarded from this network to the other side.

Input/Output Parameter data size: Non cyclic data length, typically used to read diagnostic information or configure slave parameters.

If the parameter data area is set too small, it may result in the inability to read some extended diagnostic information from the slave station; Setting too large will waste bus bandwidth.

2.3 Control Words and Status Words

To enhance remote diagnostic capabilities, X-gateway allows Control Word and Status Word to be enabled for each network interface (disabled by default).

Control Word (16 bit):

Bit 0-7: Main station mode control (only valid for main station configuration)

Position 15: Reset gateway (1 triggers restart)

Status Word (16 digits):

Bit 0-3: Gateway cycle counter (increment 1 for each successful data forwarding)

Bit 4-7: Universal error counter (increment 1 when gateway cycle exceeds 100ms)

Bit 8-11: Master station mode status (visible only to the opposite network)

Bit 12: Init bit (1 indicates that the other network interface has been initialized)

Bit 13: Run bit (1 indicates that the other side of the network is online/running)

Typical fault: If the error counter in Status Word continues to increase but the gateway is not completely offline, it is usually due to slow response time on one side of the network (such as too long PROFIBUS bus cycle setting or too many slave stations). At this point, the configuration of the master station should be checked to reduce the number of polling slave stations or increase the bus cycle time.

Common fault types and troubleshooting steps

3.1 Complete communication interruption (LED red light)

The front panel of the X-gateway has two sets of status LEDs (two per set, usually green/red):

Meaning of LED color

Green constant light communication is normal

Red constant light communication fault (such as network cable disconnection, bus conflict)

Red flashing network interface hardware failure (such as firmware damage)

Extinguish without powering on

Troubleshooting steps:

Confirm that the 24V power supply is functioning properly (measured voltage between 21.6-26.4V).

Check the physical connection of the corresponding network (such as PROFIBUS terminal resistance, EtherNet/IP network cable on/off).

Enter the Operating Status Information menu through the configuration interface and view the "Module status" and "Network status" of the interface.

If "Module status: Initialised" is displayed but "Network status: Offline" is displayed, it indicates that the interface initialization was successful but bus communication was not established (possibly due to the main station not being started or station address conflicts).

If the network interface indicator light flashes red, try restarting the gateway (using the control word to reset or power on again). If the fault persists, it may be necessary to re download the firmware or repair it.

3.2 Data mapping errors or numerical jumps

When the gateway has connected the networks on both sides, but the data read by the PLC does not match the actual physical quantity or frequently jumps, the data mapping should be checked:

Size end issue: The X-gateway defaults to using Motorola (Big End) format to store 16/32-bit values. If the PLC uses Intel (small end) format, byte swapping is required on the user side.

Control/Status Word occupancy: If Control/Status Word is enabled, the first few bytes of I/O data will be occupied by these words. For example, the first two bytes of the input I/O data area are Status Word, and the user data starts from the third byte. If the mapping offset of the PLC is not adjusted at this time, it will cause data misalignment.

Live List occupancy: When Live List is enabled in the master configuration, up to 64 slave states (each slave occupies 1 bit) will occupy the first 8 bytes of the input I/O data area.

Solution: Go to the Change Configuration menu and check if the control/status word or Live List is accidentally enabled. If these functions need to be retained, corresponding offset addresses must be recorded in the PLC program.

3.3 Loss of slave stations under master station configuration (indicated by Live List)

In the Master to Slave gateway, the master interface maintains a Live List (active slave list). This list is a 64 bit bitmap, with each bit indicating whether the slave stations with node addresses 1-64 are active (specific interpretation depends on the network protocol, such as the "data exchange" status in PROFIBUS).

If a slave station reports' Slave not active ', possible reasons may be:

Power outage or physical disconnection from the substation.

The watchdog of the slave station has timed out (the watchdog time of the slave station can be adjusted).

The I/O data length configured by the master station does not match that of the slave station.

Diagnostic operation:

Check if Live List is enabled through the configuration menu Show Fieldbus System Configuration.

If enabled, the Live List will appear at a fixed offset in the input I/O data area. It is possible to quickly determine which slave has failed by monitoring the bitmap.

For the EtherNet/IP Scanner interface (without Live List), the connection status can be viewed through another diagnostic object.

3.4 Data behavior after network offline (freezing or clearing)

When a network interface goes offline (such as a PROFIBUS cable break), the gateway will default to clearing all data sent to the other network (i.e. setting all to 0). But in some applications, such as maintaining the final effective value, it may be safer (such as valve opening). At this point, you can modify the Offline option:

Clear: Clear the output data to zero.

Freeze: Keep the output data as the last received value.

This option can be set independently for each network interface. If the application requires maintaining the output unchanged when offline, it must be changed to Freeze.

In addition, some interfaces also support Offline timeout (milliseconds) parameters. If no new data is received within this time, it will be judged as offline and the above action will be triggered.

3.5 Configuration interface cannot be connected

The configuration interface of X-gateway is the bottom RS232 port (9-pin D-sub), which requires the use of standard null modem cables (2-3 cross, 7-8 cross, 5 direct connection). The connection parameters are fixed as:

Baud rate: 57600

Data bits: 8

Verification: None

Stop position: 1

Flow control: None

If using a USB-RS232 converter, ensure that the driver is correct and the baud rate is set correctly. After entering terminal software (such as HyperTerminal, PuTTY), power on the gateway, and the screen will scroll with startup information, finally prompting Press ESC to enter configuration interface. At this point, quickly press the Esc key to enter the main menu.

If no prompt or garbled text appears:

Check if the cable is null modem (not a straight line).

Attempt to reduce the baud rate of the terminal software (sometimes the gateway actually runs at 9600? The manual specifies 57600, but some older versions may be different).

Check if the PC serial port is occupied by other programs.

Practical Configuration Menu and Detailed Parameter Explanation

4.1 Main menu navigation

After successful connection through terminal software, the main menu displays:

text

Anybus X-gateway Main menu

1 - Show gateway system information

2 - Show fieldbus system information

3 - Show gateway system configuration

4 - Show fieldbus system configuration

5 - Operating Status information

6 - Change Configuration

7 - Configuration upload/download

8 - Restart Gateway

9 - Change operation mode (Master only)

A - Administration mode

Enter the corresponding number and press enter to enter the submenu. Press Esc at any time to return to the main menu.

4.2 Viewing System Information (Diagnostic Fundamentals)

Show gateway system information: Display the bootloader version, application version, product version, and serial number. Can be used to confirm whether the firmware needs to be upgraded.

Show fieldbus system information: Display the model, firmware version, MAC address (Ethernet interface), etc. of the Upper and Lower interfaces separately. If there is a significant difference in firmware versions between the two interfaces, there may be compatibility issues.

4.3 Operating Status Information

This menu displays real-time operational data of the gateway, such as:

text

Operating Status information

PROFIBUS Master (Upper)

Cycle counter: 3

Error counter: 0

Operation mode: Stop

Module status: Initialised

Network status: Offline

Status word value (Hex): 3002

Cycle counter should normally increase several times every few seconds. If it remains unchanged for a long time, it indicates that the internal data forwarding of the gateway is stagnant.

If the Error counter continues to increase, it indicates that the gateway cycle exceeds 100ms, usually due to network overload on one side.

Operation mode can display status such as Stop/Clear/Operate for the main station interface. If it is in Stop, a control word needs to be sent to switch it to Operate (see 4.5).

The hexadecimal value of Status word value can be directly decoded. For example, 0x3002=0b0011 0000 0000 0010, it can be resolved that Run bit=1, Init bit=1, error counter=0, and loop counter=2.

4.4 Change Configuration

This is the most commonly used maintenance menu. After entering, the system will prompt "Both networks will go offline". After confirmation, you can modify the following parameters (listed in the above and below interfaces respectively):

General parameter description

Suggested values for parameter meanings

Input I/O data size: The length of input data (in bytes) for this interface is set according to application requirements and should not exceed 512

Output I/O data size: The length of the output data from this interface (in bytes) is the same as above

The action when another network is offline is usually selected as Freeze or Clear

Is the Control/Status word enabled? When the Control/Status word needs to be remotely reset or diagnosed, it should be set to Enabled

Does the Live List provide activity maps for secondary stations? When there are a large number of secondary stations and monitoring is required, set them to Enabled

Offline timeout determines the offline silence time (in milliseconds), which defaults to 0 (disabled) and can be set to 500-2000ms based on the bus cycle

Attention: After modifying the I/O data size, it must be consistent with the configuration of the opposite device (master/slave), otherwise it may cause data misalignment or communication failure.

Gateway system parameters

Reboot after disconnection: When using HMS Transport Provider (some configuration tools), whether to automatically restart the gateway if the connection is lost. Usually, keeping it enabled is sufficient to avoid the gateway not being restored after the tool is accidentally disconnected.

4.5 Change operation mode of the main station

This menu (Menu 9) is only displayed for gateways configured with the main station/scanner. The main station interface usually supports multiple operating modes, such as Stop, Clear, and Operate. The slave interface changes the master mode through the "Master Mode" bit in the control word. If the control word is disabled, it must be manually switched through this menu.

Typical scenario: The main station interface is in Stop mode, causing all slave stations to be unable to exchange data. Enter menu 9 and select Operate (or Run) to restore data exchange.

4.6 Configuration file backup and recovery (Configuration upload/download)

X-gateway supports uploading/downloading complete configuration files (config. cfg) through Ymodem protocol. This is the best way to quickly replace gateways:

Backup:

Enter the main menu → 7 → press u to start uploading.

Select "Receive Files" from the "Transfer" menu of the terminal software, choose Ymodem as the protocol, and save as config. cfg.

Recovery:

Enter the main menu → 7 → press d to start the download.

If prompted offline, press y to confirm.

Select 'Send File', choose Ymodem protocol, and send the previously saved config. cfg.

The gateway automatically restarts and the new configuration takes effect.

This method can be used to batch replicate multiple gateways or quickly restore configurations after a failure, without the need for manual item by item settings.

Power and environmental faults

5.1 Power supply abnormality

Power supply requirements: 24V DC ± 10%, maximum current 300mA. Using a non regulated power supply or voltage below 21V may cause the gateway to randomly restart or the status LED to flash.

Polarity: The power terminal has positive and negative markings (+/-), and reverse connection will not damage it but will not work.

Grounding: DIN rails must be connected to a protective earth (PE), otherwise EMC performance may decrease and communication errors may occur.

5.2 Environmental Overheating

Working temperature range: 0~+65 ° C. If installed in a closed control cabinet with poor ventilation, the gateway may exceed its upper limit, causing abnormal operation of internal chips (such as communication interruption).

Non storage temperature: -40 to+85 ° C. Extreme temperatures should be avoided during transportation or storage.

5.3 ESD precautions

The gateway contains electrostatic sensitive components inside. Before operation, contact the grounded metal or wear an anti-static wristband. More attention should be paid in dry environments.

Advanced diagnostic techniques and examples

6.1 Remote monitoring using status words

Assuming the gateway forwards the data from the PROFIBUS master to the Ethernet/IP slave. Enable Control/Status Word in Ethernet/IP configuration. At this point, the EtherNet/IP master station will receive a status word from the first 2 bytes of the input data area. Write PLC program analysis:

If the Run bit is 0, it indicates that the PROFIBUS side is not running (possibly the main station is in Stop mode).

If the Init bit is 0, it indicates that the PROFIBUS interface has not been initialized (possibly due to hardware failure or configuration error).

If the error counter is greater than 5, it indicates that the gateway forwarding delay is too high (the PROFIBUS bus load should be checked or the gateway cycle time should be increased).

6.2 Handling frequent disconnections from slave stations (PROFIBUS example)

There are 32 slave stations in the PROFIBUS network segment of a certain factory. After connecting to the Anybus X-gateway, some slave stations were found to be intermittently "Not Active" during operation. Observed frequent 0/1 switching of corresponding bits through Live List.

Solution:

Check the PROFIBUS cable shielding and terminal resistance (220 Ω at both ends).

Increase the Target Rotation Time of the PROFIBUS master station or decrease the baud rate (from 1.5M to 500k).

In the gateway configuration, set the Offline timeout to 1000ms to avoid determining that the slave station is offline due to short-term interference.

If supported by the slave station, increase its watchdog time.

6.3 Steps for Replacing the Same Model Gateway

When the gateway hardware is damaged and needs to be replaced, there is no need to reconfigure, just:

Upload the configuration file (config. cfg) from the old gateway via Ymodem.

The new gateway uses the same version of firmware (check the Application Version in System Information).

Download config. cfg to the new gateway through Ymodem.

Power on again, and the new gateway will be identical to the old gateway.

If the firmware versions are different, it is recommended to upgrade the new gateway firmware to the old version or manually reconfigure (as some parameters may not be compatible).

Systematic maintenance suggestions

Regularly check the status LED: If any network interface displays a red indicator light, immediately check the error count and status bits in the Operating Status Information.

Backup configuration: After each configuration modification, immediately upload the backup through Ymodem and label the corresponding firmware version and application scenario.

Record I/O mapping: Due to the impact of I/O data size, control/status words, and Live List on offset addresses, it is recommended to clearly indicate the meaning of each byte in the drawing.

Maintain firmware updates: Visit the HMS official website to check for firmware patches applicable to your interface, especially those involving security vulnerabilities or EMC improvements.

On site spare parts management: At least one pre fabricated backup gateway with the same configuration should be reserved. In case of a main gateway failure, replacement can be completed within 10 minutes (only rewiring and power outage restart are required).