Okuma 1911-2861 Graphic Circuit Board / CNC Control Module

Product Overview

The Okuma 1911-2861 is a printed circuit board module used in Okuma’s OSP (Okuma Sampling Path) CNC control systems. It serves as the graphics processing unit, generating video signals for the machine operator’s CRT or LCD display. This board is a critical component for the human-machine interface on Okuma lathes, machining centers, and grinding machines from the OSP 5000, 7000, and later series. It typically resides in the rack along with the main CPU and I/O boards.

Key Specifications

• Model: 1911-2861

• Product Type: Graphic circuit board / Video card

• Compatible CNC Series: Okuma OSP 5000, 7000, 5000M, 7000L, etc.

• Function: CRT/LCD display interface, graphics overlay, character generation

• Connectivity: Backplane connector (proprietary), video output (possibly VGA or RGB), signal to operator panel

• Construction: Multi-layer PCB with discrete logic and custom ASICs

• Power Supply: Supplied via backplane (+5V, ±12V or ±15V)

• Dimensions: Eurocard format (approx. 100 mm × 160 mm)

• Mounting: Single-slot in Okuma main rack

Technical Function in OSP Control

The 1911-2861 board works in conjunction with the main CPU (e.g., 1911-1842 or similar) to produce the CNC operator interface. It takes processed data from the system bus and converts it into a raster video signal. The board typically includes a character generator for alphanumeric overlays and programmable graphics for tool path display. In older OSP models, this board would drive a monochrome or color CRT; in later revisions, it may output VGA or DVI for LCD panels.

Common Symptoms and Replacement

When the 1911-2861 fails, common symptoms include a blank screen, distorted characters, flickering, or loss of the graphics overlay (tool path not visible). The board can be replaced by a qualified Okuma service technician. Before replacement, always check the backplane connectors and power supply voltages. Because Okuma parts are often specific to the machine serial number, verify the board revision matches your OSP version.

Industrial Applications

• Okuma LB series CNC lathes (OSP 5000/7000)

• Okuma MC series vertical/horizontal machining centers

• Okuma GA series grinders

• Okuma Crown and Cadet turning centers

Conclusion

The Okuma 1911-2861 graphic circuit board is an essential module for maintaining the operator display on legacy OSP-controlled machine tools. As these controls are no longer produced, original boards like the 1911-2861 are vital spares for extending the life of older Okuma machines.