OMRON FH/FHV series visual sensor controller

OMRON FH/FHV Vision System: Practical Guide to Efficient Configuration and Troubleshooting

In the field of industrial visual inspection, Omron FH/FHV series visual sensors have become the core inspection equipment for many automated production lines due to their high-speed processing, flexible system configuration, and powerful image analysis capabilities. However, facing complex on-site environments and changing production demands, engineers often encounter challenges such as communication settings, multi camera synchronization, parallel processing optimization, and image log analysis. This article combines practical applications of the FH/FHV series to provide a complete solution from system startup to advanced feature optimization, helping you quickly locate problems and improve detection efficiency.

System startup and basic configuration: avoid common "pitfalls"

1. First launch language selection and communication module settings

When the FH/FHV series is powered on for the first time, a language selection dialog box will automatically pop up. If skipped or selected incorrectly, you can reset it later by going to Tool → System settings → Startup → Startup settings → Language Setting. Please note that the system will automatically restart after the language is changed.

The selection of communication modules directly affects the efficiency of interaction with peripherals. In the Communication tab of the Startup setting, the following interfaces can be configured:

Serial (Ethernet): Supports Normal (UDP/TCP), PLC Link (compatible with SYSMAC, MELSEC, etc.)

Serial (RS-232C/422): Supports Normal and PLC Link

Parallel: Standard Parallel I/O

Fieldbus：EtherCAT、EtherNet/IP、PROFINET

Remote Operation: Allow PC remote control after activation

Key tip: Do not set both Serial (Ethernet) and Fieldbus as PLC Link at the same time, otherwise communication conflicts may occur. If using a touch screen (FH-MT12), the corresponding item must be selected in Serial (RS-232C/422), and the connection order is strictly limited (connect cable first → start touch screen → start controller).

2. Operation mode selection - match production line rhythm

FH/FHV provides four operating modes, which need to be selected according to the application scenario:

Standard mode: Single task measurement, suitable for routine testing.

Double Speed Multi input mode: With the multi input function, it allows for immediate reception of the next trigger signal after image input is completed, achieving high-speed continuous measurement. Suitable for scenarios with extremely short takt times.

Non stop adjustment mode: While the production line is running, the measurement process parameters are adjusted in the background for zero downtime optimization.

Multi line random trigger mode: A controller can support up to 8 independent detection lines, each of which can be assigned different cameras and scenes. Very suitable for parallel detection of multiple workstations.

Engineering experience: When using multi line mode, it is necessary to allocate the corresponding relationship between the camera and the line in the Camera settings, and the background color of each line should be different for differentiation. Parallel I/O signals (STEP, BUSY, OR, etc.) will be automatically mapped according to the number of lines, and the more lines there are, the fewer available I/O points.

The correct usage of multi input function and high-speed triggering

1. Multi input principle

In traditional visual systems, it is necessary to wait for the entire measurement process to be completed before accepting the next trigger. The multi input function of FH/FHV divides image input processing into "camera side processing" (exposure+image transmission) and "controller side processing" (image conversion+measurement). After the camera side processing is completed, the READY signal immediately turns on, allowing the next STEP signal to enter, thus achieving a "pipeline" parallel operation.

This function is only applicable to parallel interfaces or EtherCAT communication, and requires only one camera input processing unit in the measurement process. If multiple camera inputs or HDR mode are used, the multi input function will automatically fail.

2. Trigger Delay Setting (Inter camera Setting)

In multi camera systems, in order to avoid light interference with each other, an "Exposure start additive time" can be set. Unit 30 µ s, range -4~511. Positive values delay exposure, negative values advance exposure (caution should be exercised). At the same time, the transmission speed can be adjusted (Standard/High speed), and the high-speed mode requires the camera cable to be ≤ 5m.

Fault case: When the READY signal is OFF and STEP is input, the ERROR signal will be output. Solution: Check if the STEP signal filtering width (default 80 µ s) is too long or if noise is causing false triggering. Increasing the filtering value appropriately (such as 176 µ s) in System settings → Other → STEP settings can suppress jitter.

Parallel Processing: Maximizing the Potential of Multi Core CPUs

1. Automatic parallelization vs manual parallelization

After enabling Parallel Execute in the Operation mode setting, the system will automatically allocate processing items of the same type to different CPU cores for parallel execution. But automatic parallelization cannot finely control the splitting points.

Manual parallelization requires the addition of three special processing items in the process:

Parallelize: Mark the start of parallel blocks

Parallelize Task: Define a Task Block

Parallelize End: Mark the end of parallel blocks

The processing units within each task block are independently assigned to a core, and there is no guarantee of execution order between blocks. Therefore, logic that relies on a specific order cannot be written.

2. Parallelization limitations and performance evaluation

The task block cannot contain Camera Image Input processing items (if you need to switch cameras, use Camera Switching).

Cannot access the same file or share data in different task blocks.

Parallelization has a significant effect on the Double Speed Multi input mode (increasing the number of measurements per unit time), but may interfere with the measurement on the running side in the Non stop adjustment mode.

Practical suggestion: During the debugging phase, insert the Elapsed Time processing item, measure the execution time of each unit, and identify bottleneck tasks for parallel splitting. Attention: The post-processing time after parallelization may fluctuate due to core scheduling, and it is necessary to verify it with actual artifacts.

Scenarios and Scene Groups - Flexible Response to Multi Variety Production

1. Scene and Scene Group

Each scenario is a complete measurement process (consisting of processing units). By default, there are a maximum of 128 scenes. If more than 128 scenes are required, scene groups (up to 32 groups, with a maximum of 128 scenes per group) can be used, or the "Conversion scene group data tool" can be used to expand a single group to 1024 scenes.

The scene group data is saved by default in the controller flash memory. If the data volume is too large, it can be changed to be saved to external storage (USB/SD). Set "Save after the next scene group data in the external storage device" in Tool → Scene Group Saving Destination Settings and specify the starting group number.

2. Traps to be aware of when switching scenes

When switching scenes, the BUSY signal will remain ON for a period of time. If the external PLC detection time is too short, you can add "Scene switch time, Add time [ms]" (default 10ms) in the Measurement conditions.

If "Save scene group on switch scene" is selected when switching scenes, data will be written to flash memory, and frequent switching may affect the lifespan. Do not save unless necessary.

In multi line mode, each line independently maintains scene groups, and copying settings uses the Line Maintenance tool.

Image logs and data analysis - a powerful tool for troubleshooting NG

1. Log settings

FH/FHV supports Image Logging and Data Logging. In System settings → Other → Logging settings:

Image logging: Optional None/Only NG/All.

Destination: Save to memory, Save to memory+file (to RAMDisk or USB), Save to memory+FTP Server.

Multiple image logging: When different cameras are called multiple times in the process, set to ON to save all intermediate images.

Memory estimation: The number of log images is limited by the controller model and camera resolution. For example, the FH-5000 series is equipped with a 2MP color CMOS camera, which can store up to approximately 113 images (single camera). If four cameras are connected and multiple image logs are turned on, each measurement can store approximately (113-1)/4=28 images.

2. NG Analyzer - Quickly locate the cause of false positives

The NG Analyzer tool (Tool → NG analyzer) can batch retest saved OK/NG images and calculate the error rate of each processing unit. Operation process:

Prepare two folders, OK and NG, and put them into the corresponding images.

Perform batch measurement, and the system will display detailed data such as correlation coefficient and angle deviation for each unit.

Clicking on the failed image will take you to the parameter setting interface of the corresponding processing unit with just one click, allowing you to fine tune the threshold or region.

Typical scenario: When the lower limit of the correlation coefficient of the Search processing unit is set to 60, but the correlation coefficient of some good product images is only 55, NG Analyzer will highlight these images. At this point, the lower limit can be adjusted to 50, and then batch validation can be repeated until there are no cross judgments.

3. Remote operation and centralized management

Using the Remote Operation Tool (which requires the controller and PC to be on the same network segment, and the controller Remote Operation set to ON), remote editing of processes and monitoring of measurements can be done. Free download of PC software (requires membership registration).

For multiple controllers, Centralized Manager supports batch firmware upgrades, backup/restore settings, and configuration comparison (Compare). The comparison function can highlight the differences in system variables and scene data between two controllers, avoiding fluctuations in production line quality caused by inconsistent parameters.

Common fault codes and quick troubleshooting

The following table summarizes the most common errors encountered on site and their solutions:

Possible causes and solutions for error messages

The error concerning connection of camera was detected.  Poor contact of camera cables, failure to use designated brackets (resulting in internal circuit grounding), cables exceeding the specified length, inspection of connections to ensure isolation using metal brackets, and replacement of high-quality cables. Click on 'Detail' to view the specific camera channel status (CLK/LVAL/DMA).

Failed to start the window. Memory is insufficient. Out of memory, the model or measurement area is too large, the model registration area is reduced, the number of labels is reduced, or the scene group is saved to external storage.

Logging error: Check if the USB/SD card is recognized (using the Device Information Storage Tool to pre store device information) or clear the RAMDisk if the target is out of space or unrecognized.

PLC link error communication parameter mismatch, cable fault confirmation station number, baud rate, data format consistent with PLC; Check the terminal resistance.

The camera connected is not the same as the one used for the last save. Changing the camera model or loading old scene data to save the scene data again; If switching to a different resolution camera, it is necessary to adjust the camera model settings of all image input units.

Fan/voltage error. Check the ventilation port for fan stalling or 24V power fluctuation, and measure whether the voltage is within the range of 20.4~28.8V.

Advanced Techniques: Variables and Custom Dialogs

1. Scene variables and system variables

Scenario variable: Only valid in the current scenario, suitable for temporary calculation of data.

System variables: Can be accessed across scenes and scene groups, but cannot be accessed across lines in multi line mode.

When defining variables in the TDM editor, integer, real, string, and array types are supported, and the "Save" suffix (such as&&) can be selected to preserve variable values after power failure. Variable naming convention: The first character must be a letter, case insensitive, and reserved characters are disabled.

2. Custom dialog box

For on-site operators, a simplified settings interface can be created, exposing only necessary parameters such as thresholds and area sizes. In Window → Custom dialog settings, select Normal dialog and drag and drop numerical boxes, buttons, and other controls to associate with the external reference data number of the specific processing unit. After saving, call through Tool → Custom dialog. This feature can significantly reduce the risk of misoperation.