# Signed Integer showing 3 phase power factor for electrical metering
**URL:** https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250
**Category:** General
**Created:** [9 August 2022 19:58 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250 "2022-08-09T19:58:59Z")
**Posts on this page:** 19
**Page:** 1
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [9 August 2022 19:58 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/1 "2022-08-09T19:58:59Z")
This is a signed three phase power factor value. The manual states the following "-100 to +1000 to +100 in 1000th. It is from a 16 bit register. The most significant bit is left as read and is the sign value. When "0" the number is positive. When a "1" it is negative. The most significant value bit is 512 in binary
Example 0000\_0011\_1110\_1000 = 1000 and 1000\_0000\_0000\_0001 = -1. Thanks, Hans
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [10 August 2022 07:00 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/2 "2022-08-10T07:00:57Z")
I’m not sure what the question is, but I suspect that the node-red-contrib-buffer-parser node is the answer.
---
### Author:  [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)
#### Post date: [10 August 2022 07:12 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/3 "2022-08-10T07:12:57Z")
Can you provide a reference to the 'manual' as the maths (you quoted) doesn't make sense (to me).
Normally in signed binary values the sign-digit has a negative value (if it is set) all other bits are positive.
Your first example works out to be decimal 1000, but I can't work out how your second example equals -1
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [10 August 2022 12:08 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/4 "2022-08-10T12:08:29Z")
In a binary number, **the bit furthest to the left** is called the most significant bit (msb) and the bit furthest to the right is called the least significant bit (lsb). The MSB gives the sign of the number (sign bit) , 0 for positive and 1 for negative.
Electrical Power Factor is the relationship between the phase angles of voltage and current. When in unity the value = 1 that is represented by 1000 in this case it then closes on zero or negative zero as the angles between increase. I know negative zero is imaginary.
We need a way to change the number from negative to positive based on the left most significant bit. Does that help?
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [10 August 2022 12:17 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/5 "2022-08-10T12:17:51Z")
Can you explain how to configure node-red-buffer-parser node for this?
In a binary number, **the bit furthest to the left** is called the most significant bit (msb) and the bit furthest to the right is called the least significant bit (lsb). The MSB gives the sign of the number (sign bit) , 0 for positive and 1 for negative.
Electrical Power Factor is the relationship between the phase angles of voltage and current. When in unity the value = 1 that is represented by 1000 in this case it then closes on zero or negative zero as the angles between increase. I know negative zero is imaginary.
We need a way to change the number from negative to positive based on the left most significant bit. Does that help?
[/quote]
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [10 August 2022 13:01 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/6 "2022-08-10T13:01:23Z")
> [@HansZnarf](#):
>
> 0000\_0011\_1110\_1000 = 1000
So that binary value is just a regular 16 bit INT (or UINT for that matter)
> [@HansZnarf](#):
>
> 1000\_0000\_0000\_0001 = -1
Are you 100% certain?
In regular 16 bit encoding, 1000\_0000\_0000\_0001 is either -32767 (int) or 32769 (uint)
If that is really how the numbers have been encoded then here is one way...
```auto
[{"id":"384f507fa0042cf6","type":"function","z":"10ece3ab98e93683","name":"1000_0000_0000_0001 ","func":"const b = Buffer.alloc(2)\nb.writeUint16BE(0b1000_0000_0000_0001)\nmsg.payload = b\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":650,"y":1100,"wires":[["717232324b714dcb"]]},{"id":"aa51d42f601ceae8","type":"function","z":"10ece3ab98e93683","name":"0000_0011_1110_1000","func":"const b = Buffer.alloc(2) \nb.writeUint16BE(0b0000_0011_1110_1000)\nmsg.payload = b\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":650,"y":1060,"wires":[["717232324b714dcb"]]},{"id":"717232324b714dcb","type":"buffer-parser","z":"10ece3ab98e93683","name":"","data":"payload","dataType":"msg","specification":"spec","specificationType":"ui","items":[{"type":"int16be","name":"regularINT","offset":0,"length":1,"offsetbit":0,"scale":"1","mask":""},{"type":"uint16be","name":"regularUINT","offset":0,"length":1,"offsetbit":0,"scale":"1","mask":""},{"type":"uint16be","name":"youWant=>sign","offset":0,"length":1,"offsetbit":15,"scale":">> 15","mask":""},{"type":"uint16be","name":"youWant=>value","offset":0,"length":1,"offsetbit":15,"scale":"1","mask":"0x7FFF"}],"swap1":"","swap2":"","swap3":"","swap1Type":"swap","swap2Type":"swap","swap3Type":"swap","msgProperty":"payload","msgPropertyType":"str","resultType":"keyvalue","resultTypeType":"return","multipleResult":false,"fanOutMultipleResult":false,"setTopic":true,"outputs":1,"x":890,"y":1080,"wires":[["02fdc15c11448b36"]]},{"id":"b89f8dbdd3e04361","type":"inject","z":"10ece3ab98e93683","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":495,"y":1100,"wires":[["384f507fa0042cf6"]],"l":false},{"id":"1908b4bdb09a7523","type":"inject","z":"10ece3ab98e93683","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":495,"y":1060,"wires":[["aa51d42f601ceae8"]],"l":false},{"id":"291cdcec1cedbe62","type":"debug","z":"10ece3ab98e93683","name":"debug 55","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":1060,"y":1140,"wires":[]},{"id":"02fdc15c11448b36","type":"change","z":"10ece3ab98e93683","name":"make result","rules":[{"t":"set","p":"payload.youWant.result","pt":"msg","to":"payload.youWant.sign ? -payload.youWant.value : payload.youWant.value","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":1070,"y":1080,"wires":[["291cdcec1cedbe62"]]}]
```
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [10 August 2022 18:36 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/7 "2022-08-10T18:36:21Z")
Yes pretty certain. Took samples, ran binary results through programmer calculator, viewed the values and compared to what is displayed on device. It is an odd use but real.
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [10 August 2022 19:21 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/8 "2022-08-10T19:21:34Z")
pretty much what whatever the results are except the msb on left is the sign bit.
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 12:12 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/9 "2022-08-11T12:12:31Z")
It is essentially a 16 bit form of traditional two's complement with the 16th bit being the sign bit.
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 12:23 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/10 "2022-08-11T12:23:39Z")
Some references call this signed magnitude.
---
### Author:  [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)
#### Post date: [11 August 2022 12:33 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/11 "2022-08-11T12:33:25Z")
In a 16-bit binary pattern, where the MSB (is the sign digit) it would have a value of -32,768
This gives a numeric range from -32,768 to +32,767
If all the bits are set as in... 1111\_1111\_1111\_1111
Then I believe that should be equal to -1 (e.g. -32,768 + (+32,767) )
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 12:57 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/12 "2022-08-11T12:57:20Z")
We are basically presented with values as high as 1000 down to zero with the 16th big (MSB left) as the sign bit. We then take the result and divide by 1000 to get the answer. What code / setting do we need to make this happen?
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [11 August 2022 15:50 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/13 "2022-08-11T15:50:50Z")
> [@HansZnarf](#):
>
> We then take the result and divide by 1000 to get the answer. What code / setting do we need to make this happen?
Does the flow and function I provided not work? If it does work, then simply add one more line to the change node to divide the value by 1000.
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 16:06 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/14 "2022-08-11T16:06:59Z")
Steve-Mcl:
Regret that I am new to Node-Red coding. Like the other example that you helped me figure out (Mod 10k) I do not know enough to understand what is going on "under the hood." Did put the blocks you suggested in place but there must be more settings in the blocks that need to be set for this to work. Thanks Hans
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 16:12 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/15 "2022-08-11T16:12:42Z")
I copied that string of code that you wrote and dropped it into the buffer parser block programming area. Results still not coming out right.
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 16:34 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/16 "2022-08-11T16:34:02Z")
 Display on device is reading around -260. If jumps around since it is a live reading. Do not know how to configure the second block that you are showing in your example.
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [11 August 2022 17:03 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/17 "2022-08-11T17:03:59Z")
Flow - use `CTRL-I` to import
```auto
[{"id":"48b9b71af44a1cd9","type":"function","z":"b851e68919625d02","name":"1000_0000_0000_0001 ","func":"const b = Buffer.alloc(2)\nb.writeUint16BE(0b1000_0000_0000_0001)\nmsg.payload = b\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":1970,"y":360,"wires":[["b234510f066da748"]]},{"id":"8e40dff5f6ab0d93","type":"function","z":"b851e68919625d02","name":"0000_0011_1110_1000","func":"const b = Buffer.alloc(2) \nb.writeUint16BE(0b0000_0011_1110_1000)\nmsg.payload = b\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":1970,"y":320,"wires":[["b234510f066da748"]]},{"id":"b234510f066da748","type":"buffer-parser","z":"b851e68919625d02","name":"","data":"payload","dataType":"msg","specification":"spec","specificationType":"ui","items":[{"type":"uint16be","name":"sign","offset":0,"length":1,"offsetbit":15,"scale":">> 15","mask":""},{"type":"uint16be","name":"value","offset":0,"length":1,"offsetbit":15,"scale":"/ 1000","mask":"0x7FFF"}],"swap1":"","swap2":"","swap3":"","swap1Type":"swap","swap2Type":"swap","swap3Type":"swap","msgProperty":"payload","msgPropertyType":"str","resultType":"keyvalue","resultTypeType":"return","multipleResult":false,"fanOutMultipleResult":false,"setTopic":true,"outputs":1,"x":2210,"y":340,"wires":[["e82b5f868774848a"]]},{"id":"26afa10e45aa369e","type":"inject","z":"b851e68919625d02","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":1815,"y":360,"wires":[["48b9b71af44a1cd9"]],"l":false},{"id":"ef7260b23a524a46","type":"inject","z":"b851e68919625d02","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":1815,"y":320,"wires":[["8e40dff5f6ab0d93"]],"l":false},{"id":"5ff03b1f2adc175c","type":"debug","z":"b851e68919625d02","name":"debug 55","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":2380,"y":400,"wires":[]},{"id":"e82b5f868774848a","type":"change","z":"b851e68919625d02","name":"make result","rules":[{"t":"set","p":"payload","pt":"msg","to":"payload.sign ? -payload.value : payload.value","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":2390,"y":340,"wires":[["5ff03b1f2adc175c"]]}]
```
---
### Author:  [@HansZnarf](https://discourse.nodered.org/u/HansZnarf)
#### Post date: [11 August 2022 18:35 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/18 "2022-08-11T18:35:04Z")
Works perfectly. Thanks for the complete explanation. You made it too easy for me. Will need to do a post mortem to figure out what you did. Need to learn how to stand on my own legs. Still crawling now. Sincere Thanks,Hans
w
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [10 October 2022 18:35 UTC](https://discourse.nodered.org/t/signed-integer-showing-3-phase-power-factor-for-electrical-metering/66250/19 "2022-10-10T18:35:36Z")
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