Building an OpenPnP Pick and Place Machine? How to Integrate RAY Feeders via RS-485

For desktop SMT assembly enthusiasts and small-batch manufacturers using OpenPnP, choosing the right automated feeder system can make or break your machine’s efficiency. RAY Feeders have become a popular choice for budget-friendly, high-precision component handling. Communicating over a compact RS-485 bus, these feeders allow you to daisy-chain dozens of lanes through a single serial port.
Here is a quick guide on how to wire, configure, and define RAY Feeders in OpenPnP for your RobotDigg build or upgrade project.

Wiring & Power Specifications

Before mounting RAY Feeders onto your rail system, verify your pinouts and voltage limits to avoid damaging the logic board:
Pin Order (Top-to-Bottom): GND | B | A | VCC
Operating Voltage: 6V DC recommended (Maximum limit is 7V; strictly avoid overvoltage).
Signal Connection: Connect the differential data lines (A and B) to a standard USB-to-RS485 adapter connected to your OpenPnP host computer.
Rail Connector Pinout
(1) GND ──► Power (-)
(2) B ──► RS485 (B-)
(3) A ──► RS485 (A+)
(4) VCC ──► Power (+6V)

Setting Up the Driver in OpenPnP

RAY Feeders communicate via RS-485 using G-code style commands transmitted over a serial interface.
Open OpenPnP and navigate to Machine Setup > Drivers.
Click + (Add) and select GcodeDriver. Set the Name to 飞达主控 (or Feeder Master) and Communications Type to serial.
Configure your serial port connection with the following settings: Baud Rate: 9600 Data Bits: 8 | Stop Bits: 1 | Parity: None | Flow Control: Off

Configuring Actuators & G-Code Commands

Commands like advancing tape or checking component arrival are mapped using custom actuators in OpenPnP.
Under Machine Setup > Actuators, create ReferenceActuator instances with the value type set to Double. Then, assign the following G-code routines in your driver setup (ACTUATE_DOUBLE_COMMAND):
Actuator Function Chinese Name G-Code Command String
Tape Advance 编带前进 M600 N{IntegerValue} F1 T
Tape Reverse 编带退出 M601 N{IntegerValue} T
Position Detection 到位检测 M605 N{IntegerValue}
Set Feeder ID 设置地址 M999 N{IntegerValue} F3 T
Important Setup Note: Each RAY Feeder arrives with a default ID printed on its label. If you ever need to rewrite a feeder’s ID address using the M999 command, ensure only one feeder is powered on the rail to prevent address conflicts.

Defining Individual Feeders in OpenPnP

Once the driver and actuators are mapped, defining each physical feeder lane is straightforward:
Go to the Feeders tab in OpenPnP and click + (Add).
Choose ReferenceAutoFeeder from the feeder type list.
Assign the component part loaded in that lane (e.g., 0603-100nF) and teach your X, Y, Z pick location coordinates.
In the feeder's Actuators table, assign your created actuators (到位检测 and 编带前进) and type the feeder's specific ID Address in the Parameter Value field.
Click APPLY and hit Test Feed to watch your tape advance automatically!
By integrating RAY Feeders via RS-485, you keep your cable management ultra-clean while establishing reliable, repeatable indexing for high-speed OpenPnP assembly runs.