# Flow - Auto Start loop
**URL:** https://discourse.nodered.org/t/flow-auto-start-loop/25223
**Category:** General
**Created:** [21 April 2020 06:53 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223 "2020-04-21T06:53:39Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 06:53 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/1 "2020-04-21T06:53:40Z")
Hi,
I have a function node with a loop in it, it generates random time delays.
I want it to auto star when the PI reboots or when the flow gets re-deployed.
Is the below correct? From my function node.
```auto
const minDelay = 1, maxDelay =5; // seconds
var a = 1;
loop();
msg.payload = a;
function loop() {
if (a==1) {
node.send(msgToSend);
msgToSend = msg;
let delay = Math.random() * (maxDelay - minDelay) + minDelay;
setTimeout(loop,1000 * delay);
node.status({fill:'green',text:delay.toFixed(2)});
}
}
```
---
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [21 April 2020 07:10 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/2 "2020-04-21T07:10:01Z")
When posting code, click the button that looks like `` at the top.
I see you tried, but.....
Ok, break down:
`msg.payload = a;`
Wrong way around - I think.
You want `a` to be the `payload`.
So it should be:
`a = msg.payload`
In your loop:
You only have testing for `a == 1` What if it is another value?
Reading your original code again where: `msg.payload = a`:
So a will always be 1.
Why test at all?
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 07:17 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/3 "2020-04-21T07:17:24Z")
Thank for the reply.
I want the payload to be one always.
Debug - error message
21/04/2020, 09:12:57node: d5575e9b.cc1ac
function : (error)
"ReferenceError: msgToSend is not defined"
I have taken the test out.
```auto
const minDelay = 1, maxDelay =5; // seconds
var a = 1;
loop();
msg.payload = a;
function loop() {
node.send(msgToSend);
msgToSend = msg;
let delay = Math.random() * (maxDelay - minDelay) + minDelay;
setTimeout(loop,1000 * delay);
node.status({fill:'green',text:delay.toFixed(2)});
}
```
---
### Author:  [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)
#### Post date: [21 April 2020 07:18 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/4 "2020-04-21T07:18:53Z")
I think you have exceeded my skills sorry.
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [21 April 2020 07:44 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/5 "2020-04-21T07:44:16Z")
Whichever way you do it - you will need an inject (on start) node in front to trigger it to start running on boot.
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 07:48 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/6 "2020-04-21T07:48:37Z")
Thank you for the reply-
I have put a inject node in front of it injecting 1 on at 0.1, but it still don't start.
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [21 April 2020 08:13 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/7 "2020-04-21T08:13:13Z")
> [@ScheepersJohan](#):
>
> node.send(msgToSend);
As the error says, you have not defined msgToSend, you need `var msgToSend = something` somewhere before it is used. Alternatively perhaps you just need to change all uses of `msgToSend` to `msg` if it is actually a copy of the original msg that you want to send each time.
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 08:37 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/8 "2020-04-21T08:37:10Z")
Thank you @Colin, solved.
These two wrong way around
node.send(msgToSend);
msgToSend = msg;
Correct is way
msgToSend = msg;
node.send(msgToSend);
Or just
```
node.send(msg);
```
Can you have a var in setTimeout(loop,1000 \* delay); instead of "delay"?
---
### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [21 April 2020 08:42 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/9 "2020-04-21T08:42:20Z")
> [@ScheepersJohan](#):
>
> Can you have a var in setTimeout(loop,1000 \* delay); instead of "delay"?
What do you mean? `delay` already is a variable.
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 09:56 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/10 "2020-04-21T09:56:02Z")
Thanks for your response
Meant something link this:
```auto
msg.payload = a;
loop();
function loop() {
msg.paload = 1;
node.send(msg);
let delay1 = 10;
setTimeout(loop,1000 * delay1);
node.status({fill:'green',text:delay1.toFixed(2)});
msg.paload = 0;
node.send(msg);
let delay2 = 5;
setTimeout(loop,delay2);
node.status({fill:'green',text:delay2.toFixed(2)});
}
```
---
### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [21 April 2020 09:56 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/11 "2020-04-21T09:56:57Z")
Can you describe what you mean. From that code, I'm really not sure what you intend.
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 09:59 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/12 "2020-04-21T09:59:19Z")
send msg.payload =1 wait delay1 seconds and then send msg .payload = 0 wait delay2 seconds
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [21 April 2020 09:59 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/13 "2020-04-21T09:59:59Z")
Then what?
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 10:01 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/14 "2020-04-21T10:01:20Z")
> [@ScheepersJohan](#):
>
> send msg.payload =1 wait delay1 seconds and then send msg .payload = 0 wait delay2 seconds
send msg.payload =1 wait delay1 seconds and then send msg .payload = 0 wait delay2 seconds and then the first msg
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 10:02 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/15 "2020-04-21T10:02:02Z")
This node will have a interrupt statement in it
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 10:04 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/16 "2020-04-21T10:04:49Z")
```auto
var run = context.get('state') || false;
if (msg.topic.toLowerCase() === 'control') {
run = ! run;
}
context.set('state',run);
node.status({fill:(run) ? 'green':'red'});
var msgToSend = null;
loop();
return null;
loop();
function loop() {
msg.paload = 1;
node.send(msg);
let delay1 = flow.get("ontime");
setTimeout(loop,1000 * delay1);
node.status({fill:'green',text:delay.toFixed(2)});
msg.paload = 0;
node.send(msg);
let delay2 = flow.get("offtime");
setTimeout(loop,1000 * delay2);
node.status({fill:'green',text:delay.toFixed(2)});
}
```
---
### Author:  [@zenofmud](https://discourse.nodered.org/u/zenofmud)
#### Post date: [21 April 2020 10:09 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/18 "2020-04-21T10:09:25Z")
> [@ScheepersJohan](#):
>
> msg.paload = 1;
don't you mean `payload` instead of `paload`?
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 10:26 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/19 "2020-04-21T10:26:07Z")
Sorry Yes
```auto
var run = context.get('state') || false;
if (msg.topic.toLowerCase() === 'control') {
run = ! run;
}
context.set('state',run);
node.status({fill:(run) ? 'green':'red'});
var msgToSend = null;
loop();
return null;
loop();
function loop() {
msg.payload = 1;
node.send(msg);
let delay1 = flow.get("ontime");
setTimeout(loop,1000 * delay1);
node.status({fill:'green',text:delay.toFixed(2)});
msg.payload = 0;
node.send(msg);
let delay2 = flow.get("offtime");
setTimeout(loop,1000 * delay2);
node.status({fill:'green',text:delay.toFixed(2)});
}
```
---
### Author:  [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)
#### Post date: [21 April 2020 10:30 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/20 "2020-04-21T10:30:21Z")
@Colin This is what I want to achieve , I don't know what standard node I can use, as we suffer from a lot of power outages and most timing nodes don't give you a output once the on time are pass or you cant set the day off week from a message input.
If you have a idea I can use I will appreciate.
The code in the above is for the Pump control
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [21 April 2020 21:07 UTC](https://discourse.nodered.org/t/flow-auto-start-loop/25223/21 "2020-04-21T21:07:02Z")
I think probably the easiest way _is_ with a function node.
There are a couple of issues with your code.
I don't know what the var msgToSend line is doing, nor the loop() function after the return null.
You appear to be setting up two timers, I don't think you want to do that, you just want one, with the delay time alternating between the the two values.
[Next page](https://discourse.nodered.org/t/flow-auto-start-loop/25223.md?page=2)