Use the Modbus TCP server¶
In this document, we will focus on the Modbus/TCP server.
Ned is permanently running a Modbus TCP Server that enables Ned to communicate with a PLC, or another computer in the same network.
The Modbus/TCP server is running on port 5020 by default. It has been built on top of the pymodbus library. This enables you to make Ned communicates with a PLC, or another computer on the same network.
Introduction¶
All 4 Modbus datastores are implemented: Coils, Discrete inputs, Holding registers, Input registers. Each datastore has a different set of functionalities. Note that each datastore contains a completely different set of data.
Discrete Input and Input register are READ-ONLY tables. Those have been used to keep the robot state.
Coil and Holding Register are READ/WRITE tables. Those have been used to give user commands to the robot. Hence, those 2 tables do not contain the robot state, but the last given command.
Address tables start at 0.
Coils¶
Each address contains a 1bit value.
READ/WRITE (the stored values correspond to the last given command, not the current robot state)
Accepted Modbus functions:
- 0x01: READ_COILS
- 0x05: WRITE_SINGLE_COIL
This datastore can be used to set Digital I/O mode and state. Digital I/O numbers used for Modbus:
| Address offset | Niryo One / Ned digital IO | Ned2 digital IO |
|---|---|---|
| 0 | 1A | DI1 |
| 1 | 1B | DI2 |
| 2 | 1C | DI3 |
| 3 | 2A | DI4 |
| 4 | 2B | DI5 |
| 5 | 2C | D01 |
| 6 | SW1 | D02 |
| 7 | SW2 | D03 |
| 8 | D04 |
| Address | Description |
|---|---|
| 0-8 | Digital I/O mode (Input = 1, Output = 0) |
| 100-108 | Digital I/O state (High = 1, Low = 0) |
| 200-299 | Can be used to store your own variables |
Discrete inputs¶
Each address contains a 1bit value.
READ-ONLY
Accepted Modbus functions:
- 0x02: READ_DISCRETE_INPUTS
This datastore can be used to read Digital I/O mode and state. See the Coils section above for digital I/O number mapping.
| Address | Description |
|---|---|
| 0-8 | Digital I/O mode (Input = 1, Output = 0) |
| 100-108 | Digital I/O state (High = 1, Low = 0) |
Holding registers¶
Each address contains a 16bit value.
READ/WRITE (the stored values correspond to the last given command, not the current robot state)
Accepted Modbus functions:
- 0x03: READ_HOLDING_REGISTERS
- 0x06: WRITE_SINGLE_REGISTER
| Address | Description |
|---|---|
| 0-5 | Joints (mrad) |
| 10-12 | Position x,y,z (mm) |
| 13-15 | Orientation roll, pitch, yaw (mrad) |
| 100 | Sends Joint Move command with stored joints |
| 101 | Sends Pose Move command with stored position and orientation |
| 102 | Sends Linear Pose Move command with stored position and orientation |
| 110 | Stops current command execution |
| 150 | Is executing command flag |
| 151 | Last command result* |
| 152 | Last command data result (if not vision related) |
| 153 - 158 | Vision - Target pose result |
| 159 | Vision - Shape of the object found (-1: ANY, 1: CIRCLE, 2: SQUARE, 3: TRIANGLE, 0: NONE) |
| 160 | Vision - Color of the object found (-1: ANY, 1: BLUE, 2: RED, 3: GREEN, 0: NONE) |
| 200-299 | Can be used to store your own variables |
| 300 | Learning Mode (On = 1, Off = 0) |
| 301 | Joystick Enabled (On = 1, Off = 0) |
| 310 | Requests new calibration |
| 311 | Starts auto calibration |
| 312 | Starts manual calibration |
| 401 | Gripper open speed (100-1000) |
| 402 | Gripper close speed (100-1000) |
| 500 | Updates the tool id according to the gripper plugged (gripper 1: 11, gripper 2: 12, gripper 3: 13, vaccum pump: 31) |
| 501 | Stores the tool id |
| 510 | Opens gripper previously updated |
| 511 | Closes gripper previously updated |
| 512 | Pulls air vacuum pump with id 31 |
| 513 | Pushes air vacuum pump with id 31 |
| 520 | Updates the conveyor id and enable it |
| 521 | Detaches or disables the conveyor previously enabled and updated |
| 522 | Starts the conveyor previously enabled and updated |
| 523 | Sets the conveyor direction (backward = number_to_raw_data(-1), forward = 1) |
| 524 | Sets the conveyor speed (0-100)(%) |
| 525 | Stores the conveyor id |
| 526 | Stops conveyor previously enabled and updated |
| 600 | TCP - Enables or disables the TCP function (Tool Center Point). |
| 601 | Activates the TCP function (Tool Center Point) and defines the transformation between the tool_link frame and the TCP frame. |
| 610 | Vision - Gets target pose from relative pose, with stored relative pose and height_offset |
| 611 | Vision - Gets target pose from camera, with stored workspace name, height offset, shape and color |
| 612 | Vision - Vision pick, with stored workspace name, height offset, shape and color |
| 613 | Vision - Moves to object, with stored workspace name, height offset, shape and color |
| 614 | Vision - Detects object, with stored workspace name, shape and color |
| 620 | Vision - Stores workspace’s height offset |
| 621 | Vision - Stores relative pose x_rel |
| 622 | Vision - Stores relative pose y_rel |
| 623 | Vision - Stores relative pose yaw_rel |
| 624 | Vision - Stores requested shape (-1: ANY, 1: CIRCLE, 2: SQUARE, 3: TRIANGLE) |
| 625 | Vision - Stores requested color (-1: ANY, 1: BLUE, 2: RED, 3: GREEN) |
| 626 - max 641 | Vision - Stores workspace’s name, as a string encoded in 16 bits hex (see examples on how to store a workspace name from a client) |
| 650 | Set Analog IO - Arg: [Analog IO number, voltage 0V- 5000mV] |
‘*’ The “Last command result” gives you more information about the last executed command:
- 0: no result yet
- 1: success
- 2: command was rejected (invalid params, …)
- 3: command was aborted
- 4: command was canceled
- 5: command had an unexpected error
- 6: command timeout
- 7: internal error
Input registers¶
Each address contains a 16bit value.
READ-ONLY.
Accepted Modbus functions:
- 0x04: READ_INPUT_REGISTERS
| Address | Description |
|---|---|
| 0-5 | Joints (mrad) |
| 10-12 | Position x,y,z (mm) |
| 13-15 | Orientation roll, pitch, yaw (mrad) |
| 200 | Selected tool ID (0 for no tool) |
| 300 | Learning Mode activated |
| 400 | Motors connection up (Ok = 1, Not ok = 0) |
| 401 | Calibration needed flag |
| 402 | Calibration in progress flag |
| 403 | Raspberry Pi temperature |
| 404 | Raspberry Pi available disk size |
| 405 | Raspberry Pi ROS log size |
| 406 | Ned RPI image version n.1 |
| 407 | Ned RPI image version n.2 |
| 408 | Ned RPI image version n.3 |
| 409 | Hardware version (1 or 2) |
| 530 | Conveyor 1 connection state (Connected = 1 , Not connected = 0) |
| 531 | Conveyor 1 control status ( On = 0, Off = 1) |
| 532 | Conveyor 1 Speed (0-100 (%)) |
| 533 | Conveyor 1 direction (Backward = -1, Forward = 1) |
| 540 | Conveyor 2 connection state (Connected = 1 , Not connected = 0) |
| 541 | Conveyor 2 control status ( On = 0, Off = 1) |
| 542 | Conveyor 2 Speed (0-100 (%)) |
| 543 | Conveyor 2 direction (Backward = -1, Forward = 1) |
| 600 - 604 | Analog IO mode |
| 610 - 614 | Analog IO state in mV |
| Address offset | Niryo One / Ned analog IO | Ned2 analog IO |
|---|---|---|
| 0 | / | AI1 |
| 1 | / | AI2 |
| 2 | / | AO1 |
| 3 | / | AO2 |