Hi folks, very new to this, Node-Red and JavaScript, but I have been programming, one way or another, for years. I am trying to build a function node to process Modbus input to get, optionally, Uint or Float/Real from the 16 Bit word array, or 8 Bit raw buffer, that the Modbus getter returns. I d…

I am using that lib... As far as I am aware, and to be fair I am not aware of much :roll_eyes: the filter modbus response would do that. Unfortunately it wants a file, iofile, which it seems happy to make but I cant find where it puts it or what should be in it. I did tell it to create one, an io…

Ah ok (as I said I am not familiar with it) I thought those node would handle the output. Did you search the forum , because you can't be the only one, then again that is also an assumption :robot:

I did... I was looking specifically for the iofile thingy as I got everything else working quite quickly. I think endness is in the getter/putter so the 16bit Ints are good but that doesn't help with Uints or Floats processing the values inst hard, even longhand, although floats are a bit of a ph…

OK, so this is the plan... I want to read a block of memory, that may not necessarily contain variable of the same type in a block. This is because, well stuff just doesn't, floats are fairly rare on modulus kit but but Ints, as oppose to the native Uint 16 Bit word are and doubles, signed and uns…

Hi @Dyslexicbloke , I haven't read all your extensive and detailed posts (so I apologise up front) but based on this part... [image] Dyslexicbloke: I am trying to build a function node to process Modbus input to get, optionally, Uint or Float/Real from the 16 Bit word array, or 8 Bit raw buffer,…

Nope... But that would be ignorance not arrogance. Would ye happen to know where the documentation for that would be, I didn't come across it and it wasn't for the want of trying. let value1 = msg.payload.readFloatBE(0); let value2 = msg.payload.readInt16BE(2) I assume that there is an LE version…

[image] Dyslexicbloke: Would ye happen to know where the documentation for that would be In the link i created... [image] Steve-Mcl: helper functions the buffer object provides e.g.... [image] Dyslexicbloke: I assume that there is an LE version (Little Endian)? Absolutely […

Cant believe I missed the link, wood for trees and all that. Buffer,from(Array) Didn't find that either, probably looking and wrong JS version or something, I guess I will learn about that as I go. I was using Array.buffer in an attempt to get a ref to it., failed... and split() was kicking my be…

Steve... Thanks a bunch, that is way simpler than my previous plan, although it will needs tweaks. I haven't tested Int32's but they will not work, yet, from this device at least (Schneider M221 PLC) 16 but values are fine using BE. The float inst working but I swapped the word order in the PLC,…

Cant get array buffer refrence to work... Help please?

General

bakman2 12 April 2020 05:30 2

Welcome. I am not familiar with the data that comes from modbus, but there are modbus nodes available that can handle the problem you are trying to solve.

To install, right top hamburger menu > manage palette > install tab > search modbus

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Cant get array buffer refrence to work... Help please?

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