How to pickup an error in a function

General
1

Hello

I have a function that communicates to a devices IP address.

If the device isn't on the network, the debug window shows this:

function : (error)
request to IP_ADDR failed, reason: connect EHOSTUNREACH IP_ADDR

How do I pick this error up in the function itself or in a function after it so I can flag that the device isn't connected

2

Hard to say with such little info but at a guess try {} catch () {} - 100% depends on async await or sync or promise based code.

3

Sorry, does this go in the function node itself?

4

again ......

where is the error generated? show us the flow / code

5

Thanks for the reply and patience.

I am utilising this package:

https://github.com/bbreukelen/node-rainbird/blob/master/index.js

In the function node I have:

var temp = new RainBirdClass(MY_IP, MY_PASS);
let temp1 = await temp.getActiveZones();
msg.payload = temp1;

However, if the controller is not on the network, I see the above mentioned error in debug, which looks like it's the error returned line 139 of index.js?

Line 139: reject(err.message)

;

Instead of the function giving me an error in debug, I want to know that the controller is not on the network.

6

Open the function node, select the set-up tab, set output count to 2. This way, good messages go out of the top node, errors go out the bottom output.

const temp = new RainBirdClass(MY_IP, MY_PASS);
try {
  msg.payload = await temp.getActiveZones()
} catch (error) {
  msg.payload = "something went wrong"
  msg.error = error
  return [null, msg] // send to 2nd output 
}
return msg
7

Alternatively, add a catch node and point it at the function.