How to define an array and call a specifc value

[edwardr]

Hi guys,

This maybe very straight forward but I`m struggling to format a data array read through a modbus server.

I want to refer to msg.payload[0] of the array but in doing so I get a response saying the point is undefined which causes further issues. Anyone aware of how I could refer to the first instance in the array properly?

[Colin]

Note that payload is an object containing the properties data, which is an array, and buffer, which is a buffer. So what you want is msg.payload.data[0].
Please read the node red docs page Working with Messages which you will find very helpful I am sure. In particular it shows you how to copy the path to a value from the debug output to get the address within the message.