The A20 Digital Readout (DRO) is a versatile device designed for precision machining applications, offering a range of functions for milling, lathe, grinding, and EDM machines. It comes in two main versions: the A20-2V (2-axis) and the A20-3V (3-axis), each tailored to specific machine types.

Function Description:

The A20 DRO serves as a digital display for machine tool positions, providing accurate feedback on X, Y, and Z axes. Its core functionality includes:

Value Zero/Value Recovery: Allows users to set the current position to zero or recover previously zeroed values.
Metric and Imperial Conversion: Seamlessly switches between metric (mm) and imperial (inch) units.
Coordinate Input: Enables direct input of coordinate values.
1/2 Function: Automatically divides the displayed position value by two, useful for finding the center of a workpiece.
ABS/INC Coordinate System Conversion: Supports both absolute (ABS) and incremental (INC) coordinate systems, allowing for flexible workpiece setup and machining.
SDM Auxiliary Coordinates (200 groups): Provides 200 sets of auxiliary coordinates, which are particularly useful for medium or small batch machining. Unlike INC coordinates, SDM coordinates are based on the ABS zero point, meaning they adjust automatically if the ABS zero point changes.
Power-off Memory Function: Retains data in case of sudden power loss, automatically recovering the last known values upon power-on.
Sleep Function: Allows the DRO to enter a low-power sleep state when not in use, provided it's not in ABS mode.
REF Function: Memorizes a mechanical zero reference point of the linear scale, enabling quick retrieval of the workpiece zero point even after power cycles or loss of position.
Linear Compensation: Corrects system errors of the linear scale by inputting an actual measured length, automatically calculating and applying compensation.
Non-Linear Compensation: Addresses non-linear errors in the DRO, applicable to machines requiring high accuracy (e.g., boring, grinding machines). It supports up to 40 compensation points per axis and can be configured to start compensation from either the end point of the linear scale or the first mechanical zero reference point. Linear and non-linear compensation cannot be used simultaneously.

Special Functions:

The A20 DRO also offers advanced features tailored to specific machining operations:

PLD Function (Dividing hole on oblique line): For 2-axis and 3-axis milling machines, and 3-axis EDM machines. It calculates hole positions along an oblique line based on overall length (L-LEN) or step length (L-STEP), angle, and number of holes.
PCD Function (Dividing hole on circle): For 2-axis and 3-axis milling machines, and 3-axis EDM machines. It positions tools for drilling equally divided holes on a circle, requiring parameters like center coordinates, arc diameter, starting/end angles, and number of holes.
Smooth R Function (R-to-R): For 2-axis and 3-axis milling machines. Enables machining of complex arcs, including those connected to other arcs. Parameters include plane selection, circle center coordinates, arc radius, tool diameter, maximum cutting amount, and start/end angles.
Simple R Function: For 2-axis and 3-axis milling machines. Offers a simplified approach to arc machining with 8 preset machining ways, requiring less calculation than the Smooth R function.
Calculator Function: Provides basic arithmetic and trigonometric functions, with the ability to transfer calculated data to the X, Y, and Z axes.
Digital Filtering Function: Stabilizes the displayed value by filtering out rapid changes caused by machine vibration, improving visual comfort for the user. This function is only applicable in ABS, INC, and SDM modes and disables other functions when active.
Diameter and Radius Conversion: For 2-axis and 3-axis lathe machines. Converts X-axis display between radius and diameter values.
Axis Summing Function: For 2-axis and 3-axis lathe machines. Sums the values of the Y and Z axes and displays the total on the Y-axis.
Tool Offsets (200 sets): For 2-axis and 3-axis lathe machines. Stores 200 sets of tool offset data, allowing for quick tool changes without re-zeroing.
Taper Measuring Function: For 2-axis and 3-axis lathe machines. Facilitates the measurement of tapers on workpieces.
EDM Function: For EDM machines. Provides control for EDM machining, including setting target height, fire prevention (reverse height), exit mode, and machining direction. It can stop machining automatically when the target height is reached and offers an on/off signal output.

Important Technical Specifications:

Voltage: AC 80V-260V; 50-60HZ
Power: 15W
Working Temperature: -10℃ to 60℃
Storage Temperature: -30℃ to 70℃
Relative Humidity: <90% (at 25℃)
Axis Number: 1, 2, or 3 axes
Input Signal: 5V TTL/5V RS422
Input Signal Frequency: <50MHZ
Resolution (Linear Encoder): 0.1 µm, 0.2 µm, 0.5 µm, 1 µm, 2 µm, 2.5 µm, 5 µm, 10 µm
Highest Resolution (Rotary Encoder): <1,000,000 ppr
Weight: 1.5 KGS
Dimension: 295mm (L) * 175mm (W) * 65mm (H)
Output Port: 1.0A30VDC, 0.5A125VAC, 0.3A60VDC (DB9 Pin diagram provided for TTL and RS422 connections)

Usage Features:

User-Friendly Keypad: Features dedicated keys for axis selection, numeric input, calculation, trigonometric functions, square root, decimal point, minus input, confirmation, zeroing, 1/2 value, metric/imperial conversion, REF function, SDM coordinates, arc machining, PCD, PLD, sin/cos/tan functions (with tool offset), ABS/INC conversion, switching keys, taper measuring, axis value zeroing/recovery, and digital filtering/EDM.
Self-Checking Process: Upon power-on, the DRO performs a self-check, displaying resolution and machine mode (Mill, Lathe, Grind, EDM).
Parameter Setting: Allows configuration of encoder type (linear/rotary), resolution, counting direction (positive/negative), compensation type (linear/non-linear), imperial decimal setting, number of axes, and machine mode.
Intuitive Operation: Most functions involve a clear sequence of key presses (e.g., ENT to confirm, arrow keys to navigate).
Visual Feedback: The display provides clear indications of current mode, compensation status, and error messages (e.g., X-ERR for incorrect input).

Maintenance Features:

Troubleshooting Guide: The manual provides a comprehensive troubleshooting section for common issues such as no display, axis not counting, inaccurate counting, or grating ruler problems.
Self-Diagnosis: The DRO's self-checking process helps identify initial issues.
Error Alarms: Displays specific error messages (e.g., X-ERR) to indicate problems with input or operation.
Repair Recommendations: For persistent issues, the manual advises against self-dismantling and recommends contacting the company or dealers for professional assistance.
Grating Ruler Maintenance: Solutions for grating ruler issues include reinstalling, adjusting level, tightening screws, cleaning, and repairing damaged components.
Machine Tool Overhaul: Suggests overhauling the machine tool if its accuracy is poor.
System Reset: Recommends resetting DRO resolution or linear error compensation if settings are incorrect.

aikron A20-3V - Appendix; Parameter Dimension Troubleshooting

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