OMRON ZFX-C Vision Sensor in Practical Use

ZFX-C Intelligent Vision Sensor: A Complete Guide from System Integration to Measurement Optimization

In the field of industrial machine vision, the OMRON ZFX-C series controllers provide engineers with a "what you see is what you get" detection experience with their built-in 3.5-inch color LCD touch screen, intuitive icon menu, and powerful processing capabilities. Compared to the previous generation ZFV series, ZFX-C supports up to 2 cameras, up to 128 inspection items per bank (ZFX-C20/C25), and adds advanced features such as graphic search, flexible search, annotation, multi-color detection, and grouping. This article is based on the technical data of ZFX-C series Ver1.61, providing a complete engineering practical guide from system configuration, hardware installation, measurement project setting, position correction, calibration, parallel I/O communication to troubleshooting.

System Overview and Model Selection

The ZFX-C series controller adopts a split architecture of "controller+camera", and its core advantage lies in the built-in 3.5-inch TFT color LCD (320 × 240 pixels) and touch screen. Users can complete image confirmation and parameter settings without connecting to a computer.

1.1 Comparison of Controller Models

Model, number of connected cameras per bank, main functional differences in measurement items

ZFX-C20/C25 supports up to 2 units and up to 128 items, including graphic search, flexible search, annotation, multi-color, grouping, and log monitoring

ZFX-C10H/C15H up to 2 units and up to 32 basic function sets

ZFX-C10/C15 1 set of up to 32 basic functions, no log monitor

Selection suggestion: When detecting complex patterns (such as tilted workpieces), multi-color areas, defect detection, or data trend analysis, choose C20/C25; You can choose C10/C15 for simple detection and position offset detection.

1.2 Camera selection

ZFX-C is compatible with multiple camera types:

Camera model type Field of view setting Distance characteristics

ZFX-SR10 monochrome with lighting 4.9~8.9mm 34~49mm narrow field of view, built-in red LED

ZFX-SR50 monochrome with illumination 9.8~49mm 38~194mm wide field of view, built-in red LED

ZFX-SC10/50/90 color strip illumination 4.9~148mm 31~227mm color detection, white LED

ZFX-S monochrome camera only variable depends on the lens C-mount interface, CCTV lens needs to be optionally selected

ZFX-SC color camera only variable depending on lens C-mount interface, supports external strobe controller

Camera cable: Use ZFX-VS series standard cable (3m/8m) or ZFX-VSR series robot cable (3m). If extension is required, up to two ZFX-XC3A/XC8A extension cables can be connected in series, with a total length of no more than 19m between the controller and camera. After using the ZFX-XEQ01/XEQ02 digital equalizer, the total length can reach 28.4m.

Hardware installation and electrical connection

2.1 Camera Installation

Equipped with illuminated camera:

Determine the set distance and field of view based on the optical chart. For example, when the detection range of ZFX-SR50 is 25mm, the set distance is about 95mm.

Installation fixture: Align the two hooks of the fixture with the two grooves of the camera body, and press until it locks with a "click". Tightening torque: M4 screw 1.2N · m, 1/4 "-20UNC screw 2.6N · m.

Rotate the focus adjustment knob to make the green guide light the thinnest (in focus). Attention: Before adjusting, make sure that the knob is not in the upper or lower limit position, otherwise it may be damaged.

Camera only (C-mount type):

Optional CCTV lens (such as 3Z4S-LE SV series, focal length 3.5~100mm) and extension tube.

In the optical chart, the X-axis represents the detection range L (mm), the Y-axis represents the camera distance A (mm), and the t-value represents the length of the extension tube. For example, when using an SV-2514V lens with a detection range of 40mm and a camera distance of approximately 300mm, a 2mm extension tube is required.

2.2 Controller installation

DIN rail installation:

Hook the card hook on the controller onto the upper edge of the 35mm DIN rail.

Press down until the lower hook locks in place.

When installing other devices side by side, install the accompanying exhaust unit (ZFX-EU) to improve heat dissipation.

Panel installation:

Install the adapter using the ZFX-XPM panel.

Panel opening size: 116 ± 1mm (width) × 168 ± 1mm (height), thickness 1.6~4.8mm.

Insert the controller from the front side of the panel and fix it with installation fixtures with a tightening torque of 1.2N · m.

Heat dissipation requirements:

The controller must be installed vertically (with ventilation holes facing up/down) and cannot be placed horizontally or upside down.

Maintain a minimum distance of the indicated size from other devices, and the ambient temperature should not exceed 50 ℃. When exceeded, a fan or air conditioner needs to be installed.

2.3 Power Wiring

Power supply voltage: 24VDC ± 10% (21.6-26.4V), maximum current consumption of 1.5A (ZFX-C20/C25).

Recommended power supply: S8VS-06024 (24VDC, 2.5A).

Wiring: Use a 0.14-1.5mm ² wire with a stripped length of approximately 10mm, insert the power connector (included) and tighten the screw (torque 0.22-0.25N · m).

Ferrite core: Comes with two cores, installed at both ends of the camera cable and power cable. The power cable needs to pass through the magnetic core once.

2.4 Overview of I/O interfaces

The controller provides multiple interfaces:

Parallel interface: standard port (12 point input/23 point output) and expansion port (14 point data output)

RS-232C/422: Serial communication, maximum 115200bps

Ethernet: 100BASE-TX/10BASE-T

USB 2.0: MINI-B interface

Monitor output: Analog RGB, VGA (640 × 480)

Basic operation and measurement process

3.1 Three working modes

Mode switch position, mode purpose

MENU menu mode setting measurement conditions, registering models, adjusting images

ADJ adjusts the continuous measurement mode (without outputting results), adjusts the threshold and parameters

RUN mode actual measurement, output results to external devices

3.2 Three steps to complete measurement setup

Taking the detection of whether different products are mixed in as an example:

Step 1: Select the measurement item

MENU mode → select [Setup] → [Item] → [Shape] → [Pattern] (pattern search).

Step 2: Register the model

Select [Register model] → Move and adjust search area → [Apply].

Press the AUTO key or select [AUTO] on the screen to automatically set the optimal parameters (color filters, model images, reference values, etc.).

Step 3: Adjust the threshold and start measuring

Switch to ADJ mode and confirm that the measurement is stable and accurate.

Switch to RUN mode, input the trigger signal, and start measuring.

Important: After setting up, be sure to save the data (MENU → [System] → [Save]). Otherwise, any changes made after power failure will be lost.

Detailed Explanation of Measurement Projects

ZFX-C offers a wide range of measurement items, divided into five categories: shape, size, edge, brightness/color, and application.

4.1 Shape detection

Project Description Output

Pattern Search: Register image patterns as models to search for similar areas, supporting ± 45 ° tilt correlation values, position X/Y, and angle

Graphic Search is a model search mainly based on contour information, suitable for low contrast or partially cropped image related values, position X/Y

Flexible Search treats subtle differences as the same type and registers up to 36 model related values, locations, and model numbers

Sensitive Search detects subtle differences and automatically subdivides models (up to 100 sub models) into related values, positions, and solid color rates

Key parameters:

Search mode: High speed/Standard/High precision (sub-pixel units)

Rotation range: 0~180 °, combined with skipping angle (1~30 °)

Verification: Conduct a detailed search of all candidate points when turned on

Candidate level: 0~100, set the threshold for rough search

4.2 Dimensional Inspection

Project Description Output

Area measures the area, center of gravity, axis angle area, center of gravity X/Y, and axis angle of a specified color

Labeling counts the connected area of the measured color as one label, and outputs the number, area, position, center of gravity, perimeter, bounding rectangle, and roundness of the labels

Multi Colors simultaneously measure the area of up to 4 colors, including their respective areas and differences

Key parameters for area detection:

Fill profile: When turned on, measure the target color and the entire external area, suitable for workpieces with bumps and depressions.

Measure axis angle: Calculate axis angle when turned on (processing time increases).

Calibration: Convert pixel units to actual size when turned on.

4.3 Edge detection

Project Description Output

Position: Detecting edge coordinates within the region, edge position X/Y

Width detects the distance between two edges and the width of the edge

Count the number, spacing, width, average spacing, and average width of edges

Angle Detects edges in two areas and calculates the angle angle of two points

Key parameters for edge detection:

Measurement mode: Average/Peak/Valley

Color: Bright → Dark/Dark → Bright

Edge level: 1~99, set the threshold for determining the concentration change at the edge

Noise level: 0~255, concentration changes below this value are ignored

Noise width: 0~255, fluctuations within this width are considered noise

Partition size: 1~99, divide the area and calculate the edges

4.4 Brightness/Color Detection

Project Description Output

The average concentration and concentration deviation within the brightness measurement area, as well as the average concentration and concentration deviation

Hue (HUE) measures the average and deviation of hue, saturation, and brightness. Hue/saturation/brightness average and deviation

Key parameters for hue detection: OK ranges can be set for hue, saturation, and brightness respectively. Suggest setting a wider range of saturation and brightness to make hue judgment more stable.

4.5 Application detection

Project Description Output

Grouping: Group products, register up to 64 models, and output the index related values, positions, and index numbers of the most similar models

Defect detection includes values, locations, and numbers of defects such as scratches, dirt, and burrs

Key parameters for defect detection:

Detection size: 4-64 pixels, set according to the size of the defect. The smaller the sensitivity, the higher the sensitivity.

Detection interval: 4-64 pixels, the larger the processing time, the shorter the processing time.

Noise level: 0~255, defects below this value are ignored.

Position correction and calibration

5.1 Position correction

When the measurement target position or direction is not fixed, use the position correction function. The controller first calculates the offset and then shifts the measurement area for detection.

Position correction project:

Single model search, dual model search, graphic search, position, area, annotation, angle

settings

MENU mode → [Setup] → [Position] → [Camera 0/1] → [Position0/1] → [Correction setting]

Select the direction to be corrected: X correction, Y correction, θ correction (rotation)

Important: When using position correction, first save the image to the SD card. If different images are used for adjustment, the position correction may be incorrect and the measurement items need to be reset.

5.2 Calibration

Calibration converts measured values from pixel units to actual dimensions (mm or μ m) and can correct the origin and orientation of the coordinate system.

Three calibration methods:

Sampling input: Measure the pre registered model position, input actual coordinates, and automatically calculate calibration data. You can choose to sample at 2 or 3 points.

Specify point: Specify a point (pixel coordinates) on the image and input the actual coordinates. 2 points are suitable for the same proportion in the X/Y direction, while 3 points are suitable for different proportions.

Parameter input: Directly input the origin position and pixel magnification (0.010~9.999).

Enable calibration: Set [Calibration] to [ON] in the [Detail] settings for each measurement item.

Calculate expressions and outputs

ZFX-C supports calculating measurement values before outputting, with a maximum of 32 data expressions and 32 judgment expressions.

6.1 Available Functions

Example of Function Description

ABS absolute value ABS (RS.0)

Residual MOD (RS.0,10)

MAX/MIN Maximum/Minimum MAX (AR0, AR1, AR2, AR3)

SQRT square root SQRT (RS.0)

Average AVE (RS.0, RS.1, RS.2, RS.3)

Index of IMAX/IMIN maximum/minimum values IMAX (AR0, AR1, AR2)

SIN/COS/ATAN trigonometric function ATAN (1001. Y-1000. Y, 1001. X-1000. X)

Angle between ANGL two-point line and horizontal line ANGL (1001. Y-1000. Y, 1001. X-1000. X)

Distance between two points DIST (1000. X, 1000. Y, 1001. X, 1001. Y)

AND/OR/NOT logical operation AND (PJ.0, PJ.1)

6.2 Output Settings

Data output: MENU → [System] → [Output] → [Data output], select the output interface (RS-232C/422, parallel, SD card, etc.) USB、 Ethernet).

Output judgment: Select the parallel interface to output the judgment result.

Format setting: ASCII format can set integer and decimal places, field separators, record separators, and whether to include timestamps. Continuously output 4 bytes/data in binary format (measured value x 1000).

OR signal: can be set as a level output (held until the next output) or a single pulse output (pulse width 0-255ms).

Parallel I/O Communication and Timing

7.1 Signal Definition

Input signal (standard port):

TRIG: Measurement trigger input (minimum ON width 0.5ms)

DI0~DI7: Command input

DI8: Parallel Command Confirmation Signal

DSA: Data Transmission Request

RESET: Restart

Output signal:

OR: Comprehensive judgment result

ERROR: Error output

RUN: RUN mode indication

ENABLE: Acceptable trigger indication

GATE: Data output valid indication

DO0~DO15: Data output

STGOUT0/1: Strobe triggered output (for external light source)

7.2 Common Commands (Parallel)

Instructions for Command DI7~DI5 Parameters (DI4~DI0)

Continuous measurement during TRIG ON period of 000 *****

Switch Bank 010 00000~11111 to Bank 0~31

Switch Bank group 110 00000~11111 to group 0~31

Re register the model based on the last measured image (items 0~31)

Clear measurement data 101 00000 Clear judgment results, measurement values, log data, parallel output

7.3 Time sequence key points

Trigger measurement (handshake OFF):

T1: Trigger input ≥ 0.5ms

T2: Measurement time=Image input+Measurement (optional+display)

T3: Gate ON delay (1-1000ms)

T4: Gate ON time (1-1000ms)

T5: Output cycle (2~10000ms), must meet T3+T4<T5

ENABLE signal: It can be turned on when the image input is completed, the measurement is completed, or the display is completed. When set to "input image", the measurement is still in progress after ENABLE is turned on, and the next trigger cannot be input.

STGOUT signal: After triggering the input, it is output with a delay time of (0-60000 μ s). The pulse width can be set to (0-60000 μ s), and the polarity can be set to positive or negative.

Log Monitor and Data Analysis

ZFX-C20/C25 supports log monitor function, which can simultaneously monitor up to 3 parameters and store up to 10000 data points per parameter.

settings

MENU→[Setup]→[Add func]→[Logging monitor]→[Log0/1/2]→[Modify]

Set reference data (calculation expression), warning conditions, and log ON/OFF

Display: Select the log monitor screen in RUN/ADJ mode to view the trend chart. Adjustable scales for the horizontal axis (displaying the number of results) and vertical axis (measuring range).

Warning: The warning level can be set to display a warning when the measured value exceeds the warning range for N consecutive times (1~999), facilitating feedback before NG occurs.

Troubleshooting and Common Problems

9.1 Error Messages and Countermeasures

Possible causes and countermeasures for error messages

Unable to obtain clear images due to insufficient lighting; Low contrast; Adjust shutter speed for uneven image distribution; Use color filters; Apply smoothing or sharpening filtering; Adjust BGS level

The measurement target cannot accurately measure its position or direction due to movement, and the position correction function is enabled

Automatic setting failed. If the image is too dark or too bright, adjust the shutter speed or lighting brightness

Camera error, poor camera connection, check camera cable connection

Calibration failed. Select three points that are not on the same line and are collinear

Expression syntax error, bracket mismatch; Operator continuous check expression

SD card access error: SD card not inserted; Write protection; Insufficient space check SD card status

Incorrect password input. Incorrect password input (can be confirmed through the serial port PASSWORD command if forgotten)

9.2 Optimization of Image Quality Issues

Problem solving methods

Image darkness increases gain (× 1.0/1.5/2.0); Extend shutter time; Use the light source formula function

Low contrast, apply color filters (red/green/blue/yellow/cyan/magenta/gray/custom); Use sharpening filter

Smooth filtering is used for uneven images; adjust white balance

Tilt the reflective workpiece to install the camera; Use polarizing mirror

9.3 Common Operation Q&A

Q: How to extend the distance between the camera and the controller?

A: Use ZFX-XC3A/XC8A extension cables (up to two in series, total length ≤ 19m). After using the ZFX-XEQ01/XEQ02 digital equalizer, the total length can reach 28.4m.

Q: How to shorten the measurement time?

A: 1) Set the image rate to "high speed" (image compression, reduced accuracy); 2) Use partial functions (1/2 or 1/4 parts); 3) Set the image display to "Image Only" in RUN mode.

Q: What if the teaching is not successful?

A: 1) Check if the workpiece is within the teaching area; 2) Adjust the lighting to make the image clear; 3) For mobile teaching, check the TRIG timing (with an interval of at least 200ms).

Q: After changing the search area, is the search still conducted outside the area?

A: After changing the customer setting, the teaching must be re executed.

Q: When will the measurement conditions be saved?

A: When external TEACH signal teaching is successful; 2) When switching to RUN mode. If the TEACH button is pressed on the teaching screen and the power is directly turned off, the changes will be lost.

Maintenance and Precautions

Cleaning: Use an air blow or a soft cloth (dipped in a small amount of alcohol) to clean the front panel of the camera. Do not use diluents, benzene, acetone, or kerosene.

Ventilation film: Do not puncture or block the ventilation film with sharp objects, otherwise the protection level will fail or the front panel will condense.

Unused connector: must be covered with a protective cover to prevent static electricity and dust.

Grounding: When using a switch power supply, the FG terminal must be grounded.

Power off operation: Before connecting/disconnecting the camera cable, the controller power must be turned off, otherwise it may damage the camera.

LED safety: Equipped with illuminated cameras (ZFX-SC50/SC90, etc.) belonging to IEC62471 risk group 1, do not look directly at the light source.