OMRON H8PR electronic cam debugging

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 °