# ModBus function code 23

**URL:** <https://discourse.nodered.org/t/modbus-function-code-23/44738>\
**Category:** General\
**Created:** [26 April 2021 09:55 UTC](https://discourse.nodered.org/t/modbus-function-code-23/44738 "2021-04-26T09:55:12Z")\
**Posts on this page:** 1\
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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [26 April 2021 12:01 UTC](https://discourse.nodered.org/t/modbus-function-code-23/44738/2 "2021-04-26T12:01:45Z")

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> [@BJM](#):
>
> or if it is possible to program this in a funtion node?

It is certainly possible to write this in a function node.

[Here is a simple demo](https://discourse.nodered.org/t/how-to-create-an-modbus-tcp-alarm-status-dashboard/43041/14) i did using node-red core nodes + buffer-parser.

It doesnt do writes or support fn 23 but it is certainly not impossible (or that difficult) to do.

You would have to read the spec for FN23 to know how to format the bytes. Alternatively, you could wireshark a working implementation & work it out easily enough.

Lastly

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