Understanding Fanuc Parameter 1860: The Key to Absolute Position Data
Fanuc Parameter 1860 is a critical axis-specific setting used across various Fanuc CNC control series, including the 16, 18, 21, and 0i models. It is primarily responsible for storing and managing the current absolute position data when an absolute position detector (absolute encoder) is used. What is Fanuc Parameter 1860?
In Fanuc systems equipped with absolute encoders, the control must maintain a constant "knowledge" of where each axis is located, even after the power is cycled. While Parameter 1815 defines the status of the detector (such as whether it is enabled or if the home position is set), Parameter 1860 actually holds the numerical position data that corresponds to the mechanical position of the machine. Function: Stores the absolute position data for each axis.
Relationship to Hardware: It works in tandem with the absolute pulse coder (APC) on the motor to ensure the machine coordinate system matches the physical location of the table or tool.
Auto-Update: Under normal operation, you do not manually edit this parameter; the CNC system updates it automatically as the machine moves. Parameter 1860 vs. Parameter 1815
It is common for technicians to confuse these two, as they both relate to the absolute positioning system. Parameter 1815 Parameter 1860 Purpose Configuration and Status Bits Actual Position Data Common Bits APC (Absolute Pulse Coder), APZ (Absolute Position Zero) Numerical coordinate value Manual Action Often toggled (0 to 1) during home position resets Rarely edited manually; usually reset by a "Zero Return" When Should You Check Parameter 1860?
You will typically only interact with Parameter 1860 during major maintenance or troubleshooting of the home position. PARAMETER MANUAL
In the world of FANUC CNC systems, Parameter 1860 is a critical setting used primarily for machines equipped with absolute position detectors. It stores the current position of each axis relative to the machine zero point, ensuring the CNC "remembers" where it is even after a power cycle. What is FANUC Parameter 1860?
Parameter 1860 is a 2-word (32-bit) axis parameter. Its primary function is to maintain the absolute position data provided by the encoder. When a machine uses an absolute encoder, it doesn't need to be "homed" or "zero-returned" every morning; instead, it reads the value stored in this parameter to determine its exact location.
Data Type: 2-word (often works in conjunction with high-order bits in nearby parameters).
Key Function: Synchronizing the mechanical position of the machine with the internal coordinate system. When Does Parameter 1860 Become Important?
You will typically need to interact with this parameter during:
Battery Replacement: If the encoder batteries die, the absolute position is lost, and Parameter 1860 may need to be reset.
Motor/Encoder Replacement: Installing a new servo motor requires re-establishing the relationship between the physical axis and the CNC's internal logic.
Mechanical Crashes: A severe impact can jump the encoder or move the physical axis, making the stored value in 1860 inaccurate. Related Alarms
If there is an issue with the absolute position data, you may encounter specific APC (Absolute Pulse Coder) alarms:
Alarm 300: Request for zero return (the system has lost its position).
Alarm 306-308: Battery-related errors indicating the absolute position data is at risk. How to Set or Reset the Absolute Position
Resetting the absolute position is a precise process that involves both Parameter 1860 and Parameter 1815. Master the Fanuc Zero Return Procedure in 5 Steps
Fanuc parameter 1860 is used within the servo parameters of Fanuc 16/18/21 (and later) controls, specifically relating to backlash compensation.
Based on typical Fanuc parameter documentation and user discussions:
Function: It is generally involved in setting the compensation speed or the type of compensation applied to axis motion to counteract mechanical backlash. fanuc parameter 1860
Context: It is often updated alongside parameters 1851 (Backlash compensation amount), 1852, 1861, and 5002/5003 when calibrating tool turrets or fixing 300 APC (Absolute Position Coder) alarms.
Warning: Improperly setting this parameter can lead to inaccurate machining or damage.
For specific numerical values (e.g., what the value should be set to for a particular machine), you must refer to the Parameter List that came with your specific CNC machine tool, as these are tailored to the machine's mechanics.
To give you the most accurate advice, could you please tell me:
What specific machine tool (e.g., Mori Seiki, Doosan, Makino) is this Fanuc control on?
Are you trying to solve an alarm (like an APC or servo error) or adjust accuracy? Which Fanuc series is it? (16i, 18i, 21i-T/M etc.)
I can then help identify the correct procedure for your situation. Fanuc 21i-T Parameters - Industry Arena
In the world of FANUC CNC systems, Parameter 1860 is a critical, though often misunderstood, data field that serves as the digital link between the machine's physical location and its internal coordinate system. For technicians and engineers, mastering this parameter is essential for maintaining the high-precision "memory" of a machine tool. The Role of Absolute Position Detectors
To understand Parameter 1860, one must first look at how modern CNC machines track movement. Most contemporary systems use Absolute Pulse Coders (APC)
. Unlike incremental encoders that "forget" where they are when the power is cut, absolute encoders maintain their position even when the machine is off, provided they have battery backup. Parameter 1860 is where the system stores the current position data
received from these absolute pulse coders. It functions as a real-time ledger, recording the exact number of pulses or counts the encoder has moved from its established reference point. The Technical Mechanism
While many parameters are meant to be manually toggled by an operator (like Parameter 1815
, which establishes the zero point), Parameter 1860 is typically or updated automatically by the system. Modular Arithmetic
: The value in 1860 often uses modular arithmetic, meaning the count "wraps around" once it reaches a certain limit based on the encoder's resolution. Relationship to Zeroing
: When a technician performs a zero-return or resets the absolute position (often by toggling the APZ bit in Parameter 1815), the system recalibrates the relationship between the machine's physical "home" and the count currently residing in Parameter 1860. Why Parameter 1860 Matters
For most daily operations, a machinist will never need to look at 1860. However, it becomes vital in two specific scenarios: Recovery from APC Alarms
: If the encoder batteries die (Alarms 300-349), the machine loses its reference. While 1815 is used to tell the machine "this is zero," Parameter 1860 is where the raw data behind that zero point is tracked. Diagnostics
: If a machine is losing its position or "drifting," technicians check 1860 to see if the encoder is reporting counts correctly. If the value in 1860 changes when the axis is physically stationary—perhaps due to a failing brake or electrical noise—it signals a hardware failure. Conclusion Parameter 1860 is the "silent partner" of the more famous Parameter 1815
. While 1815 sets the rules for homing, 1860 provides the raw data that makes absolute positioning possible. Understanding its role ensures that when a machine loses its way, a technician has the diagnostic insight to bring it back to a precise home. reset the zero point using parameters 1815 and 1860 after a battery failure? FANUC? M6 toolchange position. | Practical Machinist 21 May 2014 —
A very specific topic!
Understanding FANUC Parameter 1860
FANUC is a well-known Japanese company that specializes in the development and manufacture of CNC (Computer Numerical Control) systems, robots, and other industrial automation products. In the context of FANUC CNC systems, parameters are used to configure and customize the behavior of the machine.
What is Parameter 1860?
Parameter 1860 is a specific setting in FANUC CNC systems that relates to the "Input/Output" or "I/O" configuration.
Description:
Parameter 1860 is used to specify the type of I/O device connected to the CNC system. This parameter allows you to configure the CNC system to communicate with various I/O devices, such as programmable logic controllers (PLCs), input/output units, or other CNC systems.
Setting Values:
The setting values for Parameter 1860 vary depending on the specific FANUC CNC system and the I/O device being used. Here are some common setting values:
How to Set Parameter 1860:
To set Parameter 1860, follow these general steps:
Important Considerations:
When setting Parameter 1860, ensure that:
Troubleshooting:
If you encounter issues with Parameter 1860 or I/O communication, check:
By understanding and correctly setting Parameter 1860, you can ensure proper I/O communication between your FANUC CNC system and external devices, enabling efficient and reliable machine operation.
It was a late Tuesday shift at the machine shop when the lights flickered and the old Fanuc-controlled mill went dark. When the power finally hummed back to life, the operator didn't see the usual ready screen. Instead, a series of APC (Absolute Pulse Coder) alarms blinked in angry red—the backup batteries had finally given up, and the machine had "forgotten" where it was.
The lead technician, Sarah, knew this was a high-stakes moment. In the world of Fanuc CNCs, losing your reference point isn't just a minor glitch; it’s like a pilot waking up mid-flight with no idea where the horizon is. The Hidden Tracker: Parameter 1860
Sarah dove into the system menus, bypassing the standard position screens. She was looking for Parameter 1860.
In Fanuc technical lore, Parameter 1860 is often seen as a "ghost" value. It represents the current position of the absolute encoder—a raw, digital count that tracks every rotation of the motor even when the power is off. While operators usually focus on Parameter 1815 (which actually sets the home bit), 1860 is the underlying data that makes that home bit meaningful. The Re-Homing Ritual
Sarah began the delicate process of "teaching" the machine its home again:
Setting the Stage: She switched to MDI mode and enabled Parameter Write Enable (PWE).
Clearing the Error: She navigated to Parameter 1815 and toggled the APZ (Absolute Position Zero) bit to 0. Understanding Fanuc Parameter 1860: The Key to Absolute
The Manual Move: Using the handwheel, she moved the Z-axis to its physical home position, watching the raw encoder values in the background—data that would eventually populate 1860.
The Lock-In: She flipped the APZ bit back to 1. The machine took a "snapshot" of its current state, linking the physical position to its internal digital map. The Lesson Learned
As the machine homed successfully and the alarms vanished, Sarah reminded the crew: "Parameter 1860 isn't something you change; it's something the machine remembers for you.". If that battery dies, that memory vanishes, and you're back to manual alignment and clocking holes just to get the spindle moving again.
The mill hummed back to life, its digital "brain" finally in sync with its steel limbs, ready for the next part.
Are you currently troubleshooting a battery failure or trying to re-home an axis on a Fanuc machine? FANUC? M6 toolchange position. | Practical Machinist
In the FANUC CNC system, Parameter 1860 (often referenced as
in related contexts) is a critical axis-specific parameter used for managing Absolute Position Detectors Function Overview Parameter 1860 stores the absolute position data
for each axis when an absolute pulse coder is used. Its primary role is to maintain the machine's reference position (home) even after the power is turned off, eliminating the need for a manual reference point return (homing) every time the machine is restarted. Key Characteristics Axis-Specific
: This parameter is set individually for each axis (X, Y, Z, etc.).
: It typically holds a 32-bit (binary) value representing the machine coordinate position. Dependency : It works in conjunction with Parameter 1815 , specifically: 1815#4 (APZ) : Indicates if the absolute position has been established. 1815#5 (APC) : Indicates if an absolute pulse coder is being used. Common Use Cases & Maintenance Battery Replacement
: If the backup battery for the pulse coder fails, the value in Parameter 1860 may be lost or corrupted, leading to a "300 APC Alarm: Need ZRN" (Zero Return Necessary).
: When a motor or cable is replaced, the relationship between the motor's zero point and the machine's physical home may change. Technicians must manually move the axis to the physical home and reset the reference point to update Parameter 1860. Reference Point Shift
: If you need to shift the home position slightly without moving physical switches, you may adjust the related grid shift parameters, which ultimately updates how the value in 1860 is interpreted. Safety Warning
Modifying axis parameters like 1860 can cause the machine to lose its physical orientation. To prevent crashes: Enable Parameter Write (PWE)
: You must set PWE to 1 on the Setting screen before changes are allowed. Verify Coordinates
: Always verify the "Machine" coordinate display after any change to ensure it matches the actual physical location. : Always perform a full parameter backup to a formatted CF card or external drive before editing. en.industryarena.com (APC zero return) using this parameter? How to Enable Parameter Write Enable (PWE) on a Fanuc CNC
Conclusion: Optimize 1860 for speed without sacrificing repeatability.
In the world of FANUC CNC controls, parameters are the DNA of the machine tool. They dictate everything from axis acceleration to I/O configuration. Among the hundreds of parameters, Parameter 1860 holds a critical, yet often misunderstood, role: controlling the reference position return speed (also known as "dog-type" reference return deceleration speed or approach speed).
For maintenance engineers, setup technicians, and CNC programmers, a deep understanding of Parameter 1860 is essential for reliable homing, preventing overtravel alarms, and optimizing cycle times. This article provides an exhaustive examination of Parameter 1860—its function, setup, troubleshooting, and advanced considerations.
Unlike simple ON/OFF parameters, 1860 has no universal default. The correct value depends on:
