encoder for acorn
Posted: Tue Aug 05, 2025 9:27 pm
Is this a compatible encoder? thank you for your help gentlemen
https://www.automationdirect.com/adc/sh ... -hzc30-rl2
https://www.automationdirect.com/adc/sh ... -hzc30-rl2
experimenting with ai to answer questions about CNC parts compatibility.
when prompted with the question above this is the result i got.
The Acorn Encoder Basics thread (viewtopic.php?t=921) provides detailed guidance on encoder compatibility for the Acorn CNC controller. Key points relevant to compatibility include:Encoder Type: The Acorn supports incremental quadrature encoders with A, B, and Z channels, which are standard for spindle or motor feedback in CNC applications.
Signal Type: The Acorn’s encoder inputs (via DB25 connector or H8 terminal block) support differential (line driver) signals (A, A-, B, B-, Z, Z-) or single-ended signals (A, B, Z with a common ground). The thread emphasizes that differential signals are preferred for noise immunity, but single-ended signals are supported with proper configuration.
Voltage: The Acorn encoder inputs are designed for 5 VDC signals. The thread warns that higher voltages (e.g., 12 VDC or 24 VDC) can damage the controller unless interfaced with appropriate signal conditioning (e.g., voltage dividers or converters).
Resolution: The Acorn supports a wide range of PPR, with 1000-2500 PPR being common for spindle encoders. The thread mentions that 1024 PPR is a typical choice for many applications.
Wiring: For single-ended encoders, connect A, B, and Z to the corresponding pins on the Acorn’s DB25 connector (pins 14, 15, 16 for A, B, Z, respectively) and ground to pin 7 or 8. The thread advises using shielded cables and grounding the shield to minimize noise.
Frequency: The Acorn can handle encoder pulse frequencies up to 200 kHz, sufficient for most CNC applications.
Configuration: The CNC12 software (used by Acorn) requires setting parameters for encoder PPR and whether the Z pulse is used (e.g., for rigid tapping or spindle synchronization).
Compatibility AnalysisEncoder Type and Channels:The A80H-1024-HZC30-RL2 is an incremental quadrature encoder with A, B, and Z channels, which aligns perfectly with the Acorn’s support for quadrature encoders as described in the thread.
Signal Type:The encoder’s push-pull output is a single-ended signal type, which the Acorn supports. The thread explicitly states that single-ended encoders (A, B, Z with ground) can be connected to the Acorn’s DB25 pins or H8 terminal block. However, the push-pull output actively drives both high and low states, making it more robust than open-collector outputs, which is advantageous for noise immunity in single-ended configurations.
Voltage Compatibility:The encoder operates at 5-30 VDC, which includes the 5 VDC required by the Acorn’s encoder inputs. The thread emphasizes using 5 VDC for encoder signals to avoid damaging the controller. You must power the encoder with a 5 VDC supply (available from the Acorn’s power terminals or an external 5 VDC source) to ensure compatibility. Using a higher voltage (e.g., 24 VDC) would require a signal converter to step down to 5 VDC, as cautioned in the thread.
Resolution:The encoder’s 1024 PPR is explicitly supported by the Acorn, as the thread notes that 1000-2500 PPR is common for spindle encoders. This resolution is suitable for applications like spindle feedback or rigid tapping, which the Acorn supports when configured correctly in CNC12.
Frequency:At 1024 PPR, even at a high spindle speed of 3000 RPM, the pulse frequency is 1024 * 3000 / 60 = 51.2 kHz, well within the Acorn’s 200 kHz limit noted in the thread. This ensures the Acorn can process the encoder’s output without issues.
Wiring:The thread provides wiring guidance for single-ended encoders: connect A to DB25 pin 14, B to pin 15, Z to pin 16, and ground to pin 7 or 8. The A80H-1024-HZC30-RL2’s connector pinout (available in its manual from AutomationDirect) must be mapped to these pins. The thread also recommends shielded cables, which should be used to connect the encoder to the Acorn to minimize noise, especially if the cable length exceeds a few feet.
Z-Index Pulse:The encoder includes a Z pulse, which the Acorn can use for homing, spindle synchronization, or rigid tapping. The thread notes that CNC12 parameters must be set to enable the Z pulse if required for your application (e.g., Parameter 311 for rigid tapping setup).
Potential ConsiderationsSingle-Ended vs. Differential: The A80H-1024-HZC30-RL2’s push-pull output is single-ended, while the Acorn prefers differential signals for better noise immunity in noisy CNC environments. The thread confirms single-ended encoders are compatible, but for long cable runs (>10 feet), you may need to add pull-up resistors or use a differential encoder to improve signal reliability. If noise becomes an issue, consider a differential-to-single-ended converter.
Power Supply: Ensure the encoder is powered with 5 VDC, as higher voltages could damage the Acorn’s inputs. Check the Acorn’s power terminals (e.g., H1 or H2) for a 5 VDC output or use an external 5 VDC power supply.
Software Configuration: The thread mentions setting the encoder PPR in CNC12 (e.g., Parameter 34 for spindle encoder counts). For 1024 PPR, you would typically set this to 4096 (1024 * 4 due to quadrature decoding). If using the Z pulse, configure Parameter 311 as needed.
ConclusionThe A80H-1024-HZC30-RL2 encoder is compatible with the Acorn CNC controller’s encoder inputs, as confirmed by the Acorn Encoder Basics thread, provided:The encoder is powered with 5 VDC to match the Acorn’s input requirements.
The push-pull single-ended outputs (A, B, Z) are wired correctly to the Acorn’s DB25 pins (14, 15, 16, with ground to 7 or 8) or H8 terminal block, using shielded cables.
The CNC12 software is configured with the correct PPR (e.g., 4096 counts for 1024 PPR) and Z-pulse settings if needed.
