OMRON H8PR electronic cam debugging

OMRON H8PR electronic cam debugging

In the automation control of rotating machinery, traditional mechanical cam switches are gradually being replaced by electronic cams due to issues such as wear, difficulty in adjustment, and limited angle range. The OMRON H8PR series electronic cam switch, combined with the E6F-AB3C-C absolute encoder, forms a cost-effective and high-precision angle detection and control solution. H8PR can program the encoder shaft rotation angle in units of 1 °, with a maximum of 10 ON/OFF settings per control output. The response speed can reach up to 0.2ms (5kHz), and it has a built-in battery backup program. This product is widely used in packaging machinery, printing machines, textile machinery, rotating workbenches and other occasions that require triggering output signals according to angles.

Based on the original technical data of H8PR and E6F-AB3C-C, this article systematically explains the system composition, technical specifications, installation and wiring, programming operations (including teaching function, origin compensation, rotation direction setting), fault diagnosis, and common problem handling methods in engineering applications. The aim is to help on-site engineers and technicians quickly complete debugging and maintenance.

System Overview and Core Advantages

1.1 System composition

A complete electronic cam control system includes:

Absolute rotary encoder: OMRON E6F-AB3C-C, with a resolution of 360 pulses per revolution (10 bits), capable of detecting an absolute angle of 1 °.

Electronic cam switch: H8PR series, with three specifications of 8-point, 16 point, and 24 point output. The output forms are NPN open collector (H8PR-8/16/24) and PNP (H8PR-8P/16P/24P).

Special connection cable: The encoder comes with a 2m cable and an optional E69-DF5 5m extension cable, with a total length of up to 30m.

Encoder shaft coupling: E69-C10B (optional).

1.2 Core advantages

High precision angle setting: with a minimum unit of 1 °, any angle can be programmed. A single output can set up to 10 ON/OFF segments within a 360 ° range, meeting complex timing requirements.

Fast response: When the encoder speed is 833 rpm, the response frequency is 5kHz, and the output response time is only 0.3ms (5kHz/4kHz)~1.5ms (0.5kHz). Capable of adapting to high-speed rotating machinery.

Flexible rotation direction and origin correction: The encoder axis can be selected clockwise or counterclockwise as the direction of angle increase through parameters, and the origin can be compensated within the range of -179 °~+180 ° without mechanical alignment.

Teaching function: When manually turning the device to the target position, the current angle can be directly stored in the output ON/OFF point, greatly simplifying programming.

Non volatile storage: Built in battery can backup program memory, and data can be retained for more than 10 years (25 ℃) after power failure.

Anti interference and safety design: equipped with INHIBIT input, can instantly turn off all control outputs; FORCE RUN input can prevent the program from being accidentally modified.

Detailed explanation of technical specifications

2.1 H8PR electronic cam switch

Project specifications

Power supply voltage 100~240VAC, 50/60Hz, allowable fluctuation ± 10%

Power consumption of approximately 10W (240VAC, 50Hz)

Encoder input dedicated E6F-AB3C-C, adjustable response frequency: 0.5/1/2/3/4/5kHz

Control output points 8/16/24 points (NPN or PNP)

Output capacity 30VDC, 100mA max

INHIBIT input contact or solid-state input, all control outputs are OFF when ON

FORCED RUN: Program modification is prohibited after short circuiting

Insulation resistance 100M Ω min (500VDC)

Withstand voltage 1500VAC for 1 minute

Protection level IP20 (panel installation)

Working temperature -10~55 ℃

Weight approximately 1.3kg

2.2 E6F-AB3C-C Absolute Encoder

Project specifications

Power supply 5-12VDC ± 10%

Consumption current 100mA max

Resolution 360 pulses/rev (10 bit binary)

Output code system BCD (binary coded decimal)

Output circuit NPN open collector, reverse logic (H high=0, L low=1)

Output capacity 30VDC, 35mA max, residual voltage ≤ 0.4V

Maximum response frequency 10kHz

Accuracy ± 0.5 ° max

The allowable load for the shaft is 10kgf radially and 3kgf axially

Maximum speed of 5000 rpm

Starting torque 100 gf · cm max

Protection level IP52F (dustproof, oil proof)

Working temperature -10~70 ℃

Weight approximately 500g (including 2m cable)

2.3 Output Response Schedule

Encoder response frequency output response time (max)

5 kHz, 4 kHz 0.3 ms

3 kHz 0.35 ms

2 kHz 0.5 ms

1 kHz 1.1 ms

0.5 kHz 1.5 ms

The response time refers to the total delay from the encoder angle signal input to the control output action. For high-speed rotating machinery, it is necessary to select the appropriate response frequency based on the rotational speed to avoid excessive angular lag.

Installation and wiring

3.1 Mechanical Installation

Encoder installation: E6F-AB3C-C adopts a 10mm diameter rigid shaft, which can withstand large radial and axial loads. Flexible couplings should be used to connect the tested shaft during installation to avoid eccentricity causing damage to the encoder. The installation surface should be ensured to be flat, and the torque of the fixing screws should be appropriate.

H8PR installation: adopts panel installation method, with installation clips on the back. Sufficient heat dissipation space should be left inside the control cabinet to avoid proximity to heating elements.

3.2 Connection between Encoder and H8PR

The encoder comes with a 2m dedicated cable. The definition of its signal line is as follows (as shown in the reference document):

DC power supply positive (+V): 5-12V

Power Ground (0V)

BCD code output lines (10 in total, corresponding to 360 ° BCD code)

Backup line (partially NC)

The H8PR has a dedicated encoder input terminal (25 pin or similar interface) on the back. When wiring, it is necessary to check the signal correspondence and confirm that the encoder power supply voltage meets the requirements (5-12V DC). When using extension cables, the total length should not exceed 30m. It is recommended to use shielded cables and single ended grounding.

Note: The encoder output is inverse logic (negative logic), where H high level corresponds to logic 0 and L low level corresponds to logic 1. H8PR has already adapted this logic internally, no additional inversion is required.

3.3 Control output terminals

The output terminals of H8PR are distributed in points. Taking H8PR-24P (PNP) as an example:

OUT1~OUT24: Each point corresponds to a PNP transistor output, with the load connected to the COM terminal (0V), providing 24V when the output is turned on.

COM terminal: Output common terminal (0V).

RUN output: H8PR outputs ON when in run mode.

INHIBIT input: When INHIBIT and 0V (or - COM) are short circuited, all control outputs are forcibly turned off for emergency stop or interlock.

FORCE RUN input: After short circuiting, program modification is prohibited to protect the set angle data.

Attention: The COM terminal is internally connected to the 0V input terminal, but in order to ensure that the output circuit current does not interfere with the input signal, the COM should be used as a dedicated common terminal for the output circuit.

3.4 Connection with PLC

The document provides a wiring diagram of H8PR and programmable logic controller (PLC). In general, the output of H8PR can directly drive the input module or intermediate relay of PLC. Due to its output capacity of 100mA/30V, it is sufficient to drive most 24V DC input points. If the load current exceeds 100mA, an external intermediate relay is required.

Programming and Operations

4.1 Principle of angle setting

H8PR is based on the encoder rotation angle (0~359 °), and each control output can be turned ON or OFF at the set angle position. An output point can set up to 10 ON/OFF intervals (i.e. 5 ON intervals and 5 OFF intervals). Set the resolution to 1 °.

For example, OUT1 needs to be ON from 90 ° to 180 °, ON from 225 ° to 270 °, and OFF at all other angles. Simply enter the ON angle of 90 and the OFF angle of 180 on the programming interface, and then enter the ON angle of 225 and the OFF angle of 270.

4.2 Programming Method

The H8PR front panel comes with a numeric keypad and display, supporting the following programming operations:

Direct numerical input: Enter the ON and OFF angles through the buttons.

Teaching function: When manually turning the encoder shaft to the target angle, press the "Teaching" button, and the current angle will be automatically stored in the selected ON or OFF point. This method is intuitive and avoids reading angle errors.

Origin compensation: Due to the inability of mechanical installation to achieve absolute accuracy, zero degree offset can be adjusted through the origin compensation function. Set range -179 °~+180 °. For example, if the actual zero position is 5 ° clockwise from the original zero point of the encoder, then the origin compensation is set to 5 °, and H8PR will automatically correct all angles internally.

Rotation direction selection: The angle can be set to increase clockwise or counterclockwise when the encoder shaft rotates. This depends on the direction of mechanical transmission to avoid confusion during programming.

4.3 Program Protection

To prevent accidental modifications during operation, the following methods can be used for protection:

FORCE RUN input: Short circuit the FORCE RUN terminal to 0V, and the programming keys on the front panel will be invalid.

Internal write protection: Lock parameters through menu settings.

The program is stored in RAM with battery backup, and the battery life is over 10 years. When the battery voltage is too low, the front panel will prompt a "BAT" alarm, and the battery should be replaced as soon as possible after power failure.

Application examples

5.1 Heat sealing and cutting control in packaging machinery

In a rotary packaging machine, the heat sealing knife and cutting knife need to be closed within a specific angle range. Assuming a process cycle of 360 °, the requirement is:

The sealing knife closes at 140 °~180 °

The cutting blade closes at 185 °~195 ° (briefly cuts)

Output OFF at other times

Using H8PR-8 (8-point output), OUT1 can be assigned as the seal and OUT2 as the cutter. The programming is as follows:

OUT1: ON angle=140 °, OFF angle=180 °

OUT2: ON angle=185 °, OFF angle=195 °

During actual operation, the encoder rotates synchronously with the spindle, and H8PR drives the sealing solenoid valve and cutter solenoid valve based on real-time angles.

5.2 Multi station turntable positioning

In the turntable assembly machine, it is necessary to output a pulse at each of the four positions of 0 °, 90 °, 180 °, and 270 ° to control the indexing mechanism to stop or move. Four ON/OFF segments can be set through one output point (e.g. ON 0 ° OFF 1 °, ON 90 ° OFF 91 °, ON 180 ° OFF 181 °, ON 270 ° OFF 271 °). However, it should be noted that the shortest ON interval output must meet the minimum response time of the load. The minimum angle of H8PR is set to 1 °. If the speed is high, the duration corresponding to 1 ° may be extremely short (e.g. 1 °=0.278ms at 600rpm), far less than the output response time. Therefore, when applying at high speeds, it is necessary to calculate whether the minimum ON angle is greater than the angle corresponding to the response time.

Fault diagnosis and common problems

6.1 No output or abnormal output

Possible causes and solutions for the phenomenon

All outputs are inactive, the power supply is not connected, or the INHIBIT input is valid. Check the power supply voltage and confirm that the INHIBIT terminal is open circuit

Output action but the angle is inaccurate. The origin is not calibrated or the encoder coupling is loose. Perform origin compensation or tighten the coupling

Partial output point failure, damaged output transistor or load short circuit. Check if the load current exceeds 100mA and replace the damaged output point

During operation, if the output of the chaotic encoder signal is affected by interference, check for shielding and grounding. Use a DC12V power supply and add filtering capacitors

6.2 Encoder related alarms

H8PR has built-in encoder input error detection function. If "ERR" appears, possible reasons may be:

Encoder power supply voltage abnormality (below 4.5V or above 13.2V)

Poor contact or disconnection of encoder output line

Internal circuit failure of encoder

Countermeasure: Measure the power supply voltage of the encoder, check the cable connection, and replace the encoder if necessary.

6.3 Program loss

If all set values disappear after power on, it is mostly due to the depletion of the built-in battery. Steps for battery replacement:

Open the rear battery compartment of the H8PR front panel

Remove the old battery (CR2032 or equivalent) and be careful not to short circuit it

Install a new battery and reset the program. If there is no backup, reprogramming is required.

Maintenance and upkeep

Regular inspection: Check the coupling of the encoder shaft for looseness and the output terminal screws for tightness every month.

Cleaning: Although the encoder is IP52F dustproof and oil proof, it should be regularly wiped to prevent oil stains from entering the socket in harsh environments for a long time.

Battery life management: It is recommended to replace the battery every 5 years, even if there is still electricity. Keep H8PR powered (or quickly replace) during replacement to avoid RAM data loss.

Spare parts suggestion: For critical production lines, it is recommended to stock one H8PR host and one E6F encoder for emergency replacement.