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To truly understand how Parameter 1860 works, you need to look at three key areas:
When you command a spindle to a specific orientation (say, M19 at 0 degrees), the spindle motor’s built-in position coder (pulse coder or encoder) sends feedback to the FANUC drive. Parameter 1860 provides a fine-tuned offset to correct any systematic deviation between the encoder’s zero position and the physical zero point of the spindle.
Without this correction, your rigid tapping cycles would produce out-of-tolerance threads, and your spindle would never stop at the exact same position twice.
Understanding FANUC Parameter 1860: A Comprehensive Guide
FANUC, a renowned Japanese company, is a leading manufacturer of industrial robots, CNC systems, and other automation solutions. Their products are widely used in various industries, including manufacturing, automotive, and aerospace. In this article, we'll focus on FANUC parameter 1860, a specific setting that plays a crucial role in the proper functioning of FANUC CNC systems.
What is FANUC Parameter 1860?
FANUC parameter 1860 is a setting that determines the scaling factor for the second reference velocity in a FANUC CNC system. This parameter is used to adjust the speed of the machine tool's movement along a specific axis. The value set for parameter 1860 directly affects the machine's performance, accuracy, and overall efficiency.
Why is FANUC Parameter 1860 Important?
Proper setting of parameter 1860 is essential for several reasons:
How to Set FANUC Parameter 1860
Setting parameter 1860 requires a thorough understanding of the machine's specifications, the type of movement, and the desired performance. Here are the general steps to follow:
Troubleshooting and Best Practices
To ensure optimal performance and accuracy, follow these best practices:
Conclusion
FANUC parameter 1860 plays a vital role in the proper functioning of FANUC CNC systems. Understanding the significance of this parameter and setting it correctly is essential for ensuring machine accuracy, performance, and safety. By following the guidelines outlined in this article and consulting FANUC's documentation, machine operators and technicians can optimize parameter 1860 and achieve optimal results from their FANUC CNC systems.
Parameter 1860 (often referred to as ) is a non-editable, read-only system value that represents the absolute position (encoder count) of a machine axis. This parameter is central to how a CNC system "remembers" its location without requiring a home return (homing) every time it is powered on. The Function of Parameter 1860
In Fanuc control systems, Parameter 1860 displays the current absolute position data received from the motor's pulse coder. Encoder Tracking
: It acts as a live digital readout of where the axis stands in relation to its established zero point. Automatic Synchronization : When an axis is zeroed using Parameter 1815 (APZ)
, the system captures the value in 1860 to establish the reference coordinate system. Diagnostic Use
: Since users cannot manually change this value, it is primarily used by technicians to verify if an encoder is losing counts or to troubleshoot axis "droop" or slippage during emergency stops. Practical Implications in Machine Operation
The "work" performed by Parameter 1860 is essential for maintaining precision in several scenarios: Absolute vs. Incremental
: Machines using absolute encoders rely on this parameter to bypass the need for a physical "dog-type" home switch. The control reads 1860 at startup to instantly know where the tool is. Axis Droop Monitoring
: On vertical axes (like the Z-axis) without counterweights, the spindle may drop slightly when the servos lose power (e.g., during an E-stop) before the mechanical brake engages. Technicians use Parameter 1860 to measure this displacement precisely, ensuring it doesn't exceed the machine's safety limits. System Integrity fanuc parameter 1860 work
: Because it uses modular arithmetic (the value "wraps around" once it reaches its maximum limit), it continuously tracks movement over the full travel of the axis without losing its place. Important Safety Note:
Never attempt to force-write or manipulate parameters in the 1800-series (Axis-related parameters) without referring to the official Fanuc Parameter Manual
for your specific control model (e.g., 0i, 16i, 18i), as incorrect settings can cause machine collisions. CNC Training Centre to reset your machine's zero position using these encoder counts? FANUC? M6 toolchange position. | Practical Machinist
Fanuc Parameter 1860 (often abbreviated as APZ) is used to indicate whether the zero point for an axis using an absolute pulse coder has been established. It is typically found on controls like the Fanuc 16/18/21 series and the 0i series. Function and Behavior
Purpose: This bit-type parameter identifies if the absolute position for a specific axis has been fixed.
Value "0": The zero point is not established. This usually occurs after replacing a battery (resulting in a "300 APC Alarm") or after a motor/encoder replacement.
Value "1": The absolute reference position is established. Once the zero-setting procedure is completed, the system automatically flips this bit from 0 to 1. Working with Parameter 1860
When the reference position is lost, you cannot simply change this parameter to "1" to fix it. You must physically move the machine and perform a zero-return procedure. Enable Parameter Write (PWE): Press the [SYSTEM] or [OFFSET/SETTING] key.
Find the [SETTING] soft key and set PARAMETER WRITE = 1. Note that this will trigger an alarm (typically alarm 100), which is normal. Zero-Setting Procedure: Manually jog the axis to its physical zero position.
In the parameter screen, locate Parameter 1815 (APZ bit) or 1860 (depending on the specific control model's logic). Set the relevant bit to "1" for the desired axis. Finalize:
Cycle the power to the machine to register the new absolute position.
Set PARAMETER WRITE back to 0 and clear any remaining alarms using [RESET]. Related Parameters
Parameter 1815: The primary parameter for Absolute Pulse Coder (APC) setup. Bit 4 (APZ) and Bit 5 (APC) are often configured alongside 1860.
Parameter 1851/1852: Used for Backlash Compensation once the axis is homed.
Parameter 1420: Controls the Rapid Traverse Rate for the axes after homing. How to Enable Parameter Write Enable (PWE) on a Fanuc CNC
In Fanuc CNC systems, Parameter 1860 (APOS) stores the absolute position of each axis
within the machine coordinate system as determined by the absolute pulse coder. en.industryarena.com Parameter Overview Parameter Number : Absolute position (Machine Coordinate) : 2-word axis parameter (Long Integer)
: Detection unit (typically microns or 0.0001 inches, depending on the system's increment settings) en.industryarena.com How It Works When a machine is equipped with Absolute Pulse Coders (APC)
, the CNC does not need to perform a reference return (homing) every time it is powered on. Instead, it reads the current position from the encoder and updates Parameter 1860. Origin Retention
: The value in 1860 is maintained by a battery backup in the pulse coder or servo amplifier. If battery power is lost, the value in 1860 becomes invalid, necessitating a new home position setup. Relation to Parameter 1815 : 1860 works in tandem with Parameter 1815
(APC and APZ bits). Parameter 1815.5 (APC) tells the system an absolute encoder is in use, while 1815.4 (APZ) confirms the zero point has been established. When 1815.4 is set to 1, the value currently in 1860 is recognized as the valid machine position. Coordinate Calculation
: The CNC uses the value in 1860 as the base for all other coordinate systems (Work Offsets G54-G59). If 1860 is incorrect, all machining positions will be shifted. en.industryarena.com Maintenance & Troubleshooting Series 16i/18i/21i/20i-A Maintenance Manual, GFZ-63005EN/02 Guide: Fanuc Parameter 1860 (Feed per Revolution Override)
In the world of FANUC CNC controls, Parameter 1860 serves a vital role in establishing and maintaining the machine's coordinate system. Specifically, it stores the current position of the absolute encoder for each axis in relation to the machine’s reference (home) point. 🛠️ What Parameter 1860 Does
On machines equipped with absolute encoders, Parameter 1860 acts as a "memory bank." It records the distance from the machine's zero point to the current absolute position. This allows the machine to "remember" exactly where it is, even after the power is turned off.
Axis-Specific: This is an axis-type parameter, meaning it has a unique value for X, Y, Z, and any additional axes.
Unit of Measure: Data is usually stored in detection units (the smallest increment the encoder can see), such as 0.001mm or 0.0001 inches.
Automatic Updates: Under normal operation, the control updates this value automatically as the axis moves. ⚠️ Common Scenarios & "Work" Involved
You rarely need to touch Parameter 1860 manually unless there is a communication or hardware failure. "Work" involving this parameter typically occurs in these situations: 1. Battery Failure (APC Alarm)
If the backup battery for the Absolute Pulse Coder (APC) dies while the machine is off, the absolute position data is lost.
The Symptom: You'll see an "APC" or "300" series alarm (e.g., 300 APC Alarm: Axis Need ZRN).
The Fix: You must re-home the axis manually and toggle Parameter 1815 (APZ bit) to 1 to re-establish the reference, which then refreshes the value in Parameter 1860. 2. Motor or Encoder Replacement
When you swap out a servo motor or its encoder, the new unit won't have a record of the old machine zero.
The Work: Technicians must physically move the axis to its home position and "set" the absolute zero. This process re-synchronizes the physical position with the value stored in the control. 3. "Grid Shift" Adjustments
If your machine's zero point is slightly off (e.g., after a minor crash), you might adjust Parameter 1850 (Grid Shift).
The Result: Changing the grid shift effectively shifts how the control interprets the data in Parameter 1860, moving the machine's "Home" without moving the physical encoder marker. 💡 Pro-Tip: Safety First Before making any changes to the 1800-series parameters: Back up your parameters to a USB or CF card. Record the current values of 1815 and 1860 for all axes.
Ensure you are in MDI Mode with the Parameter Write Enable (PWE) set to 1.
Here’s a concise review for Fanuc Parameter 1860 related to “work” (typically workpiece handling or robotic hand control):
Review: Fanuc Parameter 1860 (Work / Hand Control)
⭐ 4.8/5 – Essential for end-of-arm tooling & workpiece management
Overview:
Parameter 1860 in Fanuc controls the hand number or workpiece handling configuration (often used in conjunction with hand control logic or work clamping). It’s critical for robots and machining centers that manage multiple grippers or part types.
Pros:
Cons:
Best for:
Tip: Always verify 1860’s value against your workpiece definition table (often param 1861–1865). Back up your PMC parameters before editing. Name: Ext
Would you like a sample ladder logic snippet or a safety checklist for changing this parameter?
Understanding Fanuc Parameter 1860: Reference Position and Absolute Encoders
Fanuc Parameter 1860 stores the absolute position of an axis within the current rotation of the encoder. It is a critical, read-only system parameter used by the CNC to track exactly where an axis is relative to its reference (home) position. If the value in Parameter 1860 is lost or incorrect—often due to a battery failure—the machine will lose its "sense" of where it is, leading to homing alarms. What is the Function of Parameter 1860?
In Fanuc CNC systems, Parameter 1860 acts as the machine's memory for axis position data when using absolute pulse coders (APC). Unlike incremental encoders, which must hit a "limit switch" or "dog" every time the machine starts up, absolute encoders always know their position.
Role in Homing: When an axis is successfully homed (set with Parameter 1815.4 APZ), the current encoder count is saved into Parameter 1860.
Data Type: It typically uses modular arithmetic, meaning the value "wraps around" based on the encoder's pulses per revolution.
Reference Completion: If the system detects a discrepancy between the physical position and the value in 1860, it may trigger a "Request for Reference Position Return". How Parameter 1860 Works During Startup
When you power on a Fanuc machine equipped with absolute encoders:
Verification: The CNC reads the current value from the encoder.
Comparison: It compares this value against the stored data in Parameter 1860.
Validation: If they match within a certain tolerance, the machine "remembers" its position immediately without requiring a manual zero return. Troubleshooting Common 1860 Issues
Most issues related to Parameter 1860 arise after a battery failure or motor replacement.
Alarms 300-349 (APC Alarms): These indicate that the absolute position data has been lost.
Reference Position Incomplete: If you reset Parameter 1815 but the machine doesn't move to the correct spot, the value in 1860 will often change automatically once a new reference point is established.
Soft Overtravel Alarms: If the stored position in 1860 suggests the machine is outside its travel limits upon startup, you may need to power on while holding "P" and "CAN" (Cancel) to bypass the check and re-home the axis. Step-by-Step: Setting the Reference Position
Because Parameter 1860 is a system-generated value, you do not "type in" a value manually. Instead, you perform a procedure to let the CNC update it:
Master the Fanuc Zero Return Procedure in 5 Steps - CNCFixtech
This is a full guide to Fanuc Parameter 1860, explaining what it does, why it matters, and how to set it correctly.
For a machine tool builder or maintenance technician, correctly configuring Parameter 1860 is a non-negotiable step during initial commissioning or after replacing a servo motor or coder.
If you’ve adjusted Parameter 1860 but rigid tapping is still problematic, check these:
| Symptom | Likely Cause | Action | |--------|--------------|--------| | Parameter 1860 value is very large (>5000) | Incorrect initial setting or bad encoder | Reset to machine builder’s default, then re-calibrate | | Orientation works but tapping fails | Bad acceleration/deceleration times | Check Parameters 1865 (acceleration speed) and 1870 (time constant) | | Intermittent sync alarm | Electrical noise or failing spindle encoder | Check shielded cables, replace encoder | | Value resets after power cycle | Memory battery low or parameter write-protect on | Replace battery, check hardware write-protect switch |
