OMRON Cam Positioner Complete Guide

ERROR output: When the self diagnosis detects a fault, it becomes ON.

M-DET output: Output when the rotation angle matches the set value (commonly used for position arrival indication).

Chapter 3: Initial Settings and Basic Function Configuration - Get the System Moving

After the first power on or replacement of the rotary transformer, two basic initial settings must be completed.

3.1 Encoder Resolution Setting

Can be set to 360 or 720 (per revolution). This setting directly affects:

Angle step size: The minimum unit for 360 resolution is 1 °, and the minimum unit for 720 resolution is 0.5 °.

Maximum response speed: 1600 r/min at 360 resolution and 800 r/min at 720 resolution.

Number of banks: Up to 8 banks at 360 hours and up to 4 banks at 720 hours.

The maximum number of steps for each cam: at 360, the maximum output is 180 steps (one step=one pair of ON/OFF angles), and at 720, the maximum output is 360 steps.

3.2 Rotation direction setting

Set the direction of angle increase (clockwise or counterclockwise) based on the actual mechanical installation direction. This ensures that the panel display angle is consistent with the actual rotation direction, avoiding confusion during debugging.

3.3 Cam Program Writing (Basic Function)

At functional level 1 or 2, the ON and OFF angles can be directly set for each cam output in each bank through the front panel buttons. For example, set output 1 to 45 ° ON, 135 ° OFF, output 2 to 180 ° ON, 270 ° OFF, etc. Data is instantly stored in EEPROM (capable of writing up to 100000 times) without the need for battery maintenance.

Chapter 4: Advanced Application Features - Solving Mechanical and Dynamic Accuracy Problems

Production sites often encounter problems such as angle deviation, mechanical clearance, and high-speed lag. The 3F88L series offers four powerful compensation and adjustment tools.

4.1 Origin Compensation and Origin Shift

Origin compensation: static setting. When the mechanical origin of the rotary transformer does not match the zero degree position required by the equipment, any angle (1-359 ° or 1-719 °) can be defined as the new 0 ° using this parameter. This is a fixed offset.

Origin offset: dynamically triggered. In RUN mode, when the TRIG input signal changes from OFF to ON, the current position is forcibly set to 0 °. This is very useful for reciprocating movements that require automatic calibration of the origin point for each cycle.

4.2 Backlash Compensation

Mechanical transmission chains (such as gears and chains) have forward and reverse clearances, which can cause deviations between the detected angle and the actual load angle. Back clearance compensation allows setting an offset value (1-179 ° or 1-359 °), which is added or subtracted during clockwise and counterclockwise detection to "absorb" mechanical clearance. This is a key parameter for improving the accuracy of positioning repeatability.

4.3 Advance Angle Compensation

This is dynamic compensation for high-speed operation. When the speed increases, due to mechanical inertia and response delay, the cam output often lags behind the actual required position. The lead angle compensation automatically outputs the angle in advance (advance of 1-359 ° or 1-719 °) based on the current speed (1-1600 r/min). For example, in high-speed labeling or cutting applications, this function ensures that the incision accurately lands on the material marking point.

4.4 Teaching Function

Manually rotate the mechanical shaft to a specific position (such as when the material reaches the sensor position), then press the "Teach" button on the panel, and the current rotation transformer angle will be automatically written to the specified cam's ON or OFF angle. This feature greatly simplifies on-site point-to-point work and avoids repeated trial and error.

4.5 Copy Function

On multiple identical devices, a calibrated cam locator can be set as the master station, and all internal cam programs, compensation values, and setting parameters can be copied to other slave station locators at once through a dedicated communication cable (or CompoWay/F communication). This is an efficient method for batch device initialization.

4.6 Testing and Adjustment Operations

Test operation: In PRGM mode, ignore external control inputs (START, BANK, etc.), force cam output, and allow real-time modification of ON/OFF angles. Used for verifying cam angle settings without load.

Adjustment operation: In normal RUN mode, the angle is modified in real-time online, and the cam output immediately changes accordingly. Used for load fine-tuning, it can significantly shorten debugging time.

4.7 Cam Protection

To prevent key cam data from being mistakenly modified, protection levels can be set for each cam or bank. After activation, the protection must be released before modifying the ON/OFF angle.

4.8 One direction Function Settings

Some applications require the cam output to be effective only in forward or reverse rotation (e.g. one-way ratchet mechanism). Through this function, the effective direction can be individually specified for each cam.

4.9 Output Hold Function

When switching from RUN mode to PRGM mode or an error occurs, the cam output will reset by default. After enabling output hold, the output will remain in the state before switching. This can avoid actuator misoperation caused by brief mode switching.