Product Description:

Okuma’s FUB-P4M4 is a digital I/O servo module in the FUB Servo Modules series. Installed in Fieldnet-based control cabinets, it expands a CNC or PLC rack with 32 optically isolated inputs and 32 transistor outputs so motion axes can exchange status and command bits with the machine controller in real time. By combining photocoupler sensing on the input side with power MOS-FET switching on the output side, the unit handles high-speed signal traffic without adding significant propagation delay to the servo loop.

The logic section is powered from a regulated 24 VDC supply that also energizes the internal address logic operated by an external eight-position SW1 selector. Field wiring for the inputs enters through an AMP D-3400 connector, while a matching 3M No. 3428 ribbon header carries the output rows to terminal boards or relay packs. All telegrams move across the high-speed Fieldnet backplane, which clocks synchronous data at 40.00000 MHz for deterministic refresh of the module’s dual 32-bit data maps. Each map occupies 4 bytes in the master memory image, so input and output channels keep the same byte alignment for straightforward addressing.

Node addresses are set with the SW1 rotary switch, and the module is valid from I/O unit number 11 up to 127, allowing flexible slot placement in large rings. The eight switch positions provide binary coding for that range without software intervention. Output stages use a protected MOS-FET array that sources or sinks up to 2 A per channel, accommodating pilot valves or interposing relays directly. An onboard photocoupler matrix matches the input impedance to 24-volt sourcing sensors, and the ribbon header keeps internal bus lengths short to minimize skew. The module exchanges input status and output commands over the same network connection without separate interface cards.