A pair of Node-RED nodes to convert values to and from buffer/array. Supports Big/Little Endian, BCD, byte swapping and much more.
msg
property (e.g from msg.payload.myInteger
)flow
property (e.g from flow.myInteger
)global
property (e.g from global.myInteger
)msg
property (defaults to msg.payload
)msg
property. e.g. you can send results out in msg.my.nested.property
. This has the advantage of leaving the original payload in tact.msg.payload
)1FE2D7FFBE
topic
and payload
=>
in the name to create object.properties e.g. motor1=>power
will end up in msg.payload.motor1.power
.'.value
and other contextual properties included (like the item specification). Use a fat arrow =>
in the name to create object.properties e.g. motor1=>power
will end up in msg.payload.motor1.power
.'.value
property and other contextual properties included (like the item specification)0x7FFF
could be used to remove the MSB or 0b1000000000000001
to keep only MSB and LSB)
0.01
would turn 9710
into 97.1
10
would turn 4.2
into 42
>> 4
would bit shift the value 0x0070
to 0x0007
+ 42
would add an offset of 42 to the final value (New in V3.1)<<
e.g. <<2
would left shift the parsed value 2 places>>
e.g. >>2
would right shift the parsed value 2 places>>>
e.g. >>>2
would zero-fill right shift the parsed value 2 places (returns a 32bit unsigned value)+
e.g. +10
would add 10 to the parsed value -
e.g. -10
would deduct 10 from the parsed value /
e.g. /10
would divide the parsed value by 10*
e.g. *10
would multiply the parsed value by 10**
e.g. **2
would raise the parsed value to the power of 2^
e.g. ^0xf0
would XOR the parsed value with 0xf0==
e.g. ==10
would result in true
if the parsed value was equal to 10!=
e.g. !=10
would result in false
if the parsed value was equal to 10!!
e.g. !!
would result in true
if the parsed value was 1
(same as !!1 == true
) >
e.g. >10
would result in true
if the parsed value was greater than 10<
e.g. <10
would result in true
if the parsed value was less than 100.01
would turn 9710
into 97.1
or a scale of 10 would turn 50
into 500
)
Built in help
Screen shot - the flow
Screen shot - the output
Flow...
[{"id":"1194a28a.49d0ad","type":"buffer-parser","z":"c70ba4a4.e7fb58","name":"","data":"payload","dataType":"msg","specification":"{\"options\":{\"byteSwap\":[\"swap16\"],\"resultType\":\"value\",\"singleResult\":false,\"msgProperty\":\"payload\"},\"items\":[{\"name\":\"plc1/production/alphabet\",\"type\":\"string\",\"offset\":0,\"length\":26},{\"name\":\"plc1/production/status/count\",\"type\":\"int\",\"offset\":25},{\"name\":\"plc1/production/status/sequence\",\"type\":\"bcd\",\"offset\":4},{\"name\":\"plc1/machine/status/runner/temperature\",\"type\":\"int16le\",\"offset\":26},{\"name\":\"plc1/machine/status/runner/speed\",\"type\":\"int16be\",\"offset\":26},{\"name\":\"plc1/machine/status/running\",\"type\":\"bool\",\"offset\":0,\"offsetbit\":0},{\"name\":\"plc1/machine/status/warning\",\"type\":\"bool\",\"offset\":0,\"offsetbit\":1},{\"name\":\"plc1/machine/status/fault\",\"type\":\"bool\",\"offset\":0,\"offsetbit\":2}]}","specificationType":"json","x":1110,"y":480,"wires":[["858b1ecf.77b58"]]},{"id":"858b1ecf.77b58","type":"debug","z":"c70ba4a4.e7fb58","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":1350,"y":480,"wires":[]},{"id":"c22cd2e8.52649","type":"inject","z":"c70ba4a4.e7fb58","name":"Fake PLC data 16bit Array","topic":"","payload":"[25185,25699,26213,26727,27241,27755,28013,28783,29297,29811,30325,30839,31353,256,512,768,1024,1280,1536,1792,2048,2304,2560,2816,3072,3597]","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":890,"y":480,"wires":[["1194a28a.49d0ad"]]},{"id":"970db39d.106a6","type":"comment","z":"c70ba4a4.e7fb58","name":"take a array of 16bit values, byte reverse, split out several values and transmit individual messages with topic + payload","info":"","x":1160,"y":440,"wires":[]}]
Screen shot - the flow
Screen shot - the output
Flow...
[{"id":"1523dd03.6332f3","type":"buffer-parser","z":"c70ba4a4.e7fb58","name":"","data":"payload","dataType":"msg","specification":"{\"options\":{\"byteSwap\":[\"swap16\"],\"resultType\":\"object\",\"singleResult\":true,\"msgProperty\":\"data\"},\"items\":[{\"name\":\"alphabet\",\"type\":\"string\",\"offset\":0,\"length\":26},{\"name\":\"single byte pos 4\",\"type\":\"int\",\"offset\":4},{\"name\":\"bcd equiv\",\"type\":\"bcd\",\"offset\":4,\"length\":5},{\"name\":\"Array[6] of int16le\",\"type\":\"int16le\",\"offset\":26,\"length\":6},{\"name\":\"Array[6] of int16be\",\"type\":\"int16be\",\"offset\":26,\"length\":6},{\"name\":\"32 bools\",\"type\":\"bool\",\"offset\":0,\"length\":32},{\"name\":\"Array[4] of 16bits\",\"type\":\"16bit\",\"offset\":0,\"length\":4}]}","specificationType":"json","x":1110,"y":560,"wires":[["a3051c67.b82ad"]]},{"id":"a3051c67.b82ad","type":"debug","z":"c70ba4a4.e7fb58","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"data","targetType":"msg","x":1340,"y":560,"wires":[]},{"id":"9b72f1f5.1aacc","type":"inject","z":"c70ba4a4.e7fb58","name":"Fake PLC data 16bit Array","topic":"","payload":"[25185,25699,26213,26727,27241,27755,28013,28783,29297,29811,30325,30839,31353,256,512,768,1024,1280,1536,1792,2048,2304,2560,2816,3072,3597]","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":890,"y":560,"wires":[["1523dd03.6332f3"]]},{"id":"a9a2dd4c.118f9","type":"comment","z":"c70ba4a4.e7fb58","name":"take a array of 16bit values, byte reverse, split out several values and transmit one message with named objects in msg.data","info":"","x":1180,"y":520,"wires":[]}]
The simplest method is to install via the pallet manager in node red. Simply search for node-red-contrib-buffer-parser then click install
Run the following command in the root directory of your Node-RED install (usually ~/.node-red
or %userprofile%\.node-red
)
npm install node-red-contrib-buffer-parser
Or, install direct from github
npm install steve-mcl/node-red-contrib-buffer-parser
Or clone to a local folder and install using NPM
git clone https://github.com/Steve-Mcl/node-red-contrib-buffer-parser.git
npm install c:/source/node-red-contrib-buffer-parser
none :smile: