node-red-contrib-pccc

A Node-RED node to interact with some Allen-Bradley PLCs using PCCC protocol. Based on the awesome work of plcpeople/nodepccc.

Installing

You can install this node directly from the "Manage Palette" menu in the Node-RED interface. There are no external dependencies or compilation steps.

Alternatively, run the following command in your Node-RED user directory - typically ~/.node-red on Linux or %HOMEPATH%\.nodered on Windows

    npm install node-red-contrib-pccc

Usage

Just drop a pccc in node to read and watch addresses of the PLC, or a pccc out node to write values to the PLC. Both of them need a pccc endpoint, where you can configure the address of the PLC (IP Address, port, and routing), the cycle time and timeout values, and the list of addresses available on the PLC.

Addressing

The addresses follow the same syntax of what would be used on RSLogix, so for example B3:0/0 addresses the bit 0 of byte 0 in the file B3, and F8:1 points to the float 1 at the file F8.

About routing

The configuration of routing follows a very special syntax for now

0x01,0x00,0x01,0x00
  |    |    |    |
  |    |    |    +-- 0: The slot of the PLC
  |    |    +------- 1: Route over the backplane
  |    +------------ Reserved, always zero
  +----------------- 1: Number of words (1 = 2 bytes) of the routing section

You most likely just want to change the last number to the slot of the PLC when connecting to ControlLogix/CompactLogix controllers

Wishlist

• Validate addresses
• Improve routing configuration

Bugs and enhancements

Please share your ideas and experiences on the Node-RED forum, or open an issue on the page of the project on GitHub

License

Copyright: (c) 2016-2021, ST-One Ltda.

GNU General Public License v3.0+ (see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt)