# \[Announce\] new Raspberry Pi redPlc nodes

**URL:** <https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257>\
**Category:** Share Your Nodes\
**Created:** [2 February 2021 18:46 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257 "2021-02-02T18:46:00Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)\
**Post date:** [2 February 2021 18:46 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/1 "2021-02-02T18:46:00Z")

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> **[node-red-contrib-redplc-rpi-pcf8574](https://flows.nodered.org/node/node-red-contrib-redplc-rpi-pcf8574)**
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> redPlc pcf8574/a Module

> **[node-red-contrib-redplc-rpi-pcf8575](https://flows.nodered.org/node/node-red-contrib-redplc-rpi-pcf8575)**
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> redPlc pcf8575 Module

> **[node-red-contrib-redplc-rpi-mcp23008](https://flows.nodered.org/node/node-red-contrib-redplc-rpi-mcp23008)**
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> redPlc mcp23008 Module

> **[node-red-contrib-redplc-rpi-mcp23017](https://flows.nodered.org/node/node-red-contrib-redplc-rpi-mcp23017)**
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> redPlc mcp23017 Module

> **[node-red-contrib-redplc-rpi-mcp23s08](https://flows.nodered.org/node/node-red-contrib-redplc-rpi-mcp23s08)**
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> redPlc mcp23s08 Module

> **[node-red-contrib-redplc-rpi-mcp23s17](https://flows.nodered.org/node/node-red-contrib-redplc-rpi-mcp23s17)**
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> redPlc mcp23s17 Module

> **[node-red-contrib-redplc-unipi11](https://flows.nodered.org/node/node-red-contrib-redplc-unipi11)**
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> redPlc Unipi 1.1 Module

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**Author:** ![SonoraTechnical](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/sonoratechnical/32/20033_2.png) [@SonoraTechnical](https://discourse.nodered.org/u/SonoraTechnical)\
**Post date:** [3 February 2021 16:31 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/2 "2021-02-03T16:31:28Z")

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Will you be expanding this to other hardware like the PCA9685?  
I'll check out your nodes. I've focused on the NCD nodes for any mcp23008 use cases myself... I'll see how your node works...

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<div class="post-metadata">

**Author:** ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)\
**Post date:** [3 February 2021 18:47 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/3 "2021-02-03T18:47:17Z")

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Hi,  
I must order a pca9685 module and 5-10 servos for test next time. Today I work on nodes for using the chip nodes using without redPlc ladder logic environment. Also I work on Adc and Dac nodes.

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**Author:** ![SonoraTechnical](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/sonoratechnical/32/20033_2.png) [@SonoraTechnical](https://discourse.nodered.org/u/SonoraTechnical)\
**Post date:** [3 February 2021 20:06 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/4 "2021-02-03T20:06:54Z")

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I've just downloaded the redPLC ladder logic environment. I have a perfect environment to test it out... Multiple Tank Levels in Multiple Vessels, Water Top-offs, Water Fill, Water Draining, etc... I'm actually using mcp32008 nodes from NDC, but I will try your's for the Level Input....

I'll work over the weekend and provide updates in the Project Thread:

[Sonoran Desert Fish Nook - NodeRed DIY Aquarium Controller](https://discourse.nodered.org/t/aquarium-controller-raspberry-pi-4b-node-red-atlas-scientific-i2c-devices-ncd-i2c-relay-board/25839)

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<div class="post-metadata">

**Author:** ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)\
**Post date:** [3 February 2021 20:44 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/5 "2021-02-03T20:44:56Z")

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Oh looks fine.  
I work before on a hardware plc project.  
There are lot of problems on running the plc task.  
Plc's runs in an endless loop (very simple):

1. Read data from input hardware and updates plc memory.
2. Executes the control program (laddder logic) where only plc memory is touched. The ladder logic starts on first rung left element and ends on last rung right rung element.
3. Writes the plc memory to output hardware if changed.  
redPlc works on same method.

The problem is, when the plc memory is changed from outside  
(e.g pressing button in Dashboard) during step 2, the logic isn't  
consistency. This is a asynchron data change and produce malfunctions in logic. This can be solve with save the async  
data in a buffer and updates the plc memory in step 1.  
Therefore I must write nodes, that accept data from async source and syncronize with the redPlc task.  
Its a hard job to write this, but it is necessary.

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<div class="post-metadata">

**Author:** ![SonoraTechnical](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/sonoratechnical/32/20033_2.png) [@SonoraTechnical](https://discourse.nodered.org/u/SonoraTechnical)\
**Post date:** [3 February 2021 21:51 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/6 "2021-02-03T21:51:15Z")

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So, should I wait for you to finish those nodes, so that I do not get frustrated using the ladder logic nodes?

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<div class="post-metadata">

**Author:** ![iiot2k](https://avatars.discourse-cdn.com/v4/letter/i/8baadc/32.png) [@iiot2k](https://discourse.nodered.org/u/iiot2k)\
**Post date:** [4 February 2021 07:00 UTC](https://discourse.nodered.org/t/announce-new-raspberry-pi-redplc-nodes/40257/7 "2021-02-04T07:00:45Z")

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You can start it. Later you can add the part, where data exchange with external nodes (e.g Dashboard) are made.  
If you need analog value handling, please wait. I hope, that I add the analog handling this week.