If you encounter a (Request for Reference Position Return), check parameter 1860. If the APRS bit is 0, the CNC has "forgotten" where it is. You will need to enable Parameter Write (PWE) and perform the homing procedure specified by your machine tool builder to reset it.
user wants a comprehensive article on FANUC parameter 1860, focusing on how it works. This is a technical topic related to FANUC CNC controls. I need to provide detailed information about this parameter, including its function, configuration, and impact on machine operation. To cover all aspects, I will perform multiple searches to gather information about parameter 1860, including its meaning, configuration, usage, and related parameters. search results show some relevant links. Result 0 appears to be a parameter manual page mentioning parameter 1860 for reference point value. Result 1 is a Chinese Q&A site that says 1860 is for "First acceleration for Two-Stage Backlash Acc. function". Result 2 is a list of common Fanuc parameters. Result 3 is a search result for "Read Write Parameters" which might be relevant for parameter modification. Result 4 is a Focas tutorial. Result 5 is a Chinese blog post about parameter modification. Result 6 is about PMC parameters. Result 7 is a forum post mentioning 1860. Result 8 is about PMC parameters. To understand parameter 1860, I need to open result 0, result 1, result 2, result 3, result 7, and result 8. opened pages provide some information. The parameter manual page shows that parameter 1815 bit 0 (NRT) controls whether reference point values (parameter 1860, 1861) are changed or not for a rotary axis with a scale that has no revolution data. The Chinese Q&A page says 1860 is for "First acceleration for Two-Stage Backlash Acc. function". The common parameters page might list 1860 but it's not shown in the snippet. The forum posts indicate that 1860 and 1861 are involved in absolute encoder synchronization and reference point values. The search results also show that 1860 is related to "Reference point value". To further investigate, I will search for "FANUC parameter 1860 reference point". 0 might be relevant. Let's open it. page clarifies that parameter 1860 and 1861 hold reference position data for rotary axes with absolute position detectors. Let's search for "FANUC parameter 1860 1861". 3 is a Japanese blog that lists 1860 as "Value 1 for origin setting of absolute position detector". Let's open it.'s search for "1860 absolute position detector".'s search for "FANUC parameter 1860 backlash".'s search for "FANUC parameter 1860 function".'s search for "FANUC parameter 1860 PDF". need to gather more information about parameter 1860. Let's search in Chinese for "FANUC 1860 参数". also want to find information about the "Two-Stage Backlash Acc. function". Let's search for that. 6 seems promising. Let's open it. page shows that parameter 1860 is used as "1ST ACC VALUE" for the two-stage backlash acceleration function. I also need to understand "Reference point value" function. Let's search for "Parameter 1860 reference point value FANUC".'s also search for "FANUC parameter 1860 dual position feedback". search results show that parameter 1860 can have different functions depending on the model and options. I will structure the article to cover its role in absolute position detection (Reference Point Value), Backlash Acceleration (1st ACC Value), and the Two-Stage Backlash Acceleration function. I will also mention the related parameter 1861. The article will include sections on understanding the parameter, its functions, configuration, related parameters, step-by-step setup, best practices, and conclusion. I will cite the sources gathered.Mastering FANUC Parameter 1860: A Comprehensive Guide to Enhancing Machine Precision and Performance**
Proper setting of parameter 1860 is essential for several reasons:
: Most machines use "Automatic Setting" (set via Parameter 1902), where the system detects the amplifiers in order. The Role of 1860
In modern Fanuc systems (like the 16i, 18i, 21i, and 0i series), the control communicates with servo amplifiers through a high-speed fiber-optic bus called Automatic vs. Manual fanuc parameter 1860 work
The old maintenance chief called it superstition. The engineers called it electromagnetic noise. HR called it a safety issue and posted memos about unauthorized personnel. We riffled through delivery manifests; nothing explained the hair. The CCTV, once enhanced, revealed nothing except grain and the predictable path of machines.
Discover why Parameter 1860 is often omitted from standard manuals in this Practical Machinist discussion
You'll see an "APC" or "300" series alarm (e.g., 300 APC Alarm: Axis Need ZRN ).
Note: This parameter interacts with Parameter 1821 (Detected Unit/CMR). If 1821 is set incorrectly, 1860 will not solve the issue. If you encounter a (Request for Reference Position
I began to chart the occurrences, one column for date, one for machine ID, one for the parameter value. When I mapped the timestamps against the plant's CCTV, the pattern was petty and precise: every instance happened near the late shift, in a corner of the floor where the emergency exits met a dead-end aisle stacked with crates of tooling bits. The footage revealed nothing—no intruders, no mischief—only the machine, breathing mechanics, and the slow sweep of the floor cleaner.
While exact bit designations vary slightly between specific control generations (such as the older FANUC 16i/18i series versus the modern 0i-F Plus and 30i platforms), Parameter 1860 is universally tied to positioning feedback settings: Series 16i-18i-MODEL B - Parameter Manual.pdf - Drivesul
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.
As we have seen, Parameter 1860's function is context-dependent. Modifying it without knowing whether it's acting as a backlash acceleration value or a reference point position could lead to a machine crash or severe positioning errors. user wants a comprehensive article on FANUC parameter
When troubleshooting vibrations, noise, or "servo lag" errors (like Error 410 or 420), Parameter 1860 is one of the key parameters to adjust. Increasing the value makes the motion smoother but slower; decreasing it makes the motion faster but potentially jerkier. Setting and Adjusting Parameter 1860
: For this parameter to be active, Parameter 1815 #5 (APC) must be set to 1 (indicating an absolute pulse coder is in use).
Explain how to (like 1620 or 1861) for better acceleration.