# Monitoring IoT by Ping
**URL:** https://discourse.nodered.org/t/monitoring-iot-by-ping/23718
**Category:** General
**Created:** [27 March 2020 09:47 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718 "2020-03-27T09:47:02Z")
**Posts on this page:** 10
**Page:** 2
### Author:  [@ezequiel\_barros](https://discourse.nodered.org/u/ezequiel_barros)
#### Post date: [31 March 2020 12:59 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/21 "2020-03-31T12:59:40Z")
@Steve-Mcl
Good Morning. I changed the command and now it worked (this is listing which rasp is on or not)
Thanks a lot for the help
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [31 March 2020 13:10 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/22 "2020-03-31T13:10:38Z")
Hi Dave.
I personally think there are valid reasons for a flow to know it's host OS. This is but one case where there is not really a need to develop a node (it's perfectly achievable pretty much out of the box using exec node which is part of the standard install - so I don't get why we would have to jump through hoops to know the host OS)
But I don't disagree with your stand point either - as most here know, you have far more insight on the inner workings and forward vision of node red & I respect your opinion.
Thanks for taking the time to respond.
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [31 March 2020 13:28 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/23 "2020-03-31T13:28:03Z")
Hi Steve, no problem. Same way we really don't want to add anything browser specific in if we can help it - we would rather tings work all over the place if possible,
I'm also happy to look at pull requests for the Ping node - There are known techniques to make an input optional, and there's nothing to stop the input being a csv list or array for example.
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### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [31 March 2020 13:30 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/24 "2020-03-31T13:30:43Z")
> [@dceejay](#):
>
> There are known techniques to make an input optional
Pretty sure you showed by how to do that on my cron+ node 🙂
> [@dceejay](#):
>
> I'm also happy to look at pull requests for the Ping node
I might take a look 👍
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### Author:  [@edstobi](https://discourse.nodered.org/u/edstobi)
#### Post date: [31 March 2020 17:52 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/25 "2020-03-31T17:52:40Z")
Hello
Great what developed from my request. I am happy to read this process. Thanks to all of you. 😊
@ dceejay
You are writing the there are known techniques to make an input optional. Can a beginner do that or do they refer more to pure programming?
@Steve-Mcl
I have a question about:
> //store ping item
> pingResults[thisPing.name] = thisPing;
>
> //save pingResults in flow context
> flow.set("pingResults",pingResults);
> I have to watch my limited space on store and save. I only have a few MB left on my SD card of my PI. Or does all of this take place in the temporary memory
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [31 March 2020 17:55 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/26 "2020-03-31T17:55:44Z")
> [@edstobi](#):
>
> I have to watch my limited space on store and save. I only have a few MB left on my SD card of my PI. Or does all of this take place in the temporary memory
It's in memory only (as long as you haven't setup file based context storage). If you don't know what I mean then it's very likely it's in memory only.
> [@edstobi](#):
>
> You are writing the there are known techniques to make an input optional. Can a beginner do that or do they refer more to pure programming?
Dave is referring to node development (a somewhat separate issue to your requirements)
---
### Author:  [@edstobi](https://discourse.nodered.org/u/edstobi)
#### Post date: [31 March 2020 17:59 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/27 "2020-03-31T17:59:54Z")
I thank you and everyone else who helps me
Node Red makes me really fun to learn something new.
😀 THX Marc (EDSTOBI)
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [4 April 2020 16:27 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/28 "2020-04-04T16:27:13Z")
> [@Colin](#):
>
> It might be better to use node-red-node-ping
We can now with the updated version of [node-red-node-ping](https://flows.nodered.org/node/node-red-node-ping)
It now has 2 modes: **Timed** [_original mode_] or **Triggered** [_new mode_] & also accepts a CSV list of IPs or an array of objects - greatly simplifying pinging multiple devices.
Simplified flow screen shot
Simplified flow...
```auto
[{"id":"51f7207a.baa53","type":"inject","z":"a878aaaa.79a018","name":" ***Setup devices to ping here***","topic":"","payload":"[{\"name\":\"router\",\"host\":\"192.168.1.1\"},{\"name\":\"tv\",\"host\":\"192.168.1.51\"},{\"name\":\"smart speaker\",\"host\":\"192.168.1.52\"},{\"name\":\"bad device\",\"host\":\"192.168.2.99\"}]","payloadType":"json","repeat":"20","crontab":"","once":false,"onceDelay":0.1,"x":320,"y":260,"wires":[["cf66e372.27656"]]},{"id":"99c8413.a9a79c","type":"template","z":"a878aaaa.79a018","name":"build html table","field":"html","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"\n\n \n | Name | \n Host | \n Status | \n
\n {{#tableData}}\n \n | {{{name}}} | \n {{host}} | \n {{{stateInfo}}} | \n
\n {{/tableData}}\n
","x":660,"y":320,"wires":[["c9452322.9411d","90592906.29a578"]]},{"id":"c9452322.9411d","type":"debug","z":"a878aaaa.79a018","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":830,"y":360,"wires":[]},{"id":"3988b1f3.69647e","type":"inject","z":"a878aaaa.79a018","name":"","topic":"","payload":"[{\"name\":\"router\",\"ip\":\"192.168.0.1\"},{\"name\":\"tv\",\"ip\":\"192.168.0.51\"},{\"name\":\"smart speaker\",\"ip\":\"192.168.0.52\"},{\"name\":\"bad device\",\"ip\":\"192.168.1.99\"}]","payloadType":"json","repeat":"30","crontab":"","once":false,"onceDelay":0.1,"x":230,"y":320,"wires":[["4e150f7e.63b67"]]},{"id":"4e150f7e.63b67","type":"function","z":"a878aaaa.79a018","name":"convert pingResults to array","func":"let pingResults = flow.get(\"pingResults\") || {}\nlet now = new Date();\n\nlet tableData = [];\nfor (let k in pingResults) {\n let r = pingResults[k];\n r.age = now - r.timestamp\n if(r.age > 18000){\n r.state = \"old\"\n }\n if(r.state == \"ok\"){\n r.rowclass = \"good\";\n r.stateInfo = ' OK'\n } else if(r.state == \"ng\") {\n r.rowclass = \"bad\";\n r.stateInfo = ' NG'\n } else {\n r.rowclass = \"unknown\";\n r.stateInfo = ' ' + r.state\n }\n tableData.push(r);\n}\n\nmsg.tableData = tableData\n\nreturn msg;","outputs":1,"noerr":0,"x":440,"y":320,"wires":[["99c8413.a9a79c","71f260f1.aacbf"]]},{"id":"cf66e372.27656","type":"ping","z":"a878aaaa.79a018","mode":"triggered","name":"","host":"","timer":"20","inputs":1,"x":530,"y":260,"wires":[["ddef4dbb.e8897"]]},{"id":"cf6a929c.6311a","type":"debug","z":"a878aaaa.79a018","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":830,"y":260,"wires":[]},{"id":"ddef4dbb.e8897","type":"function","z":"a878aaaa.79a018","name":"Store Results","func":"let pingResults = flow.get(\"pingResults\") || {}\nlet thisPing = pingResults[msg.topic] || {};\nlet success = msg.payload !== false && msg.payload >= 0;\n\nthisPing.name = msg.ping.name;\nthisPing.host = msg.ping.host;\nthisPing.timestamp = new Date();\nthisPing.responseTime = success ? msg.payload : null;\nthisPing.state = success ? \"ok\" : \"ng\" ;\n\npingResults[msg.topic] = thisPing;//store ping obj in pingResults\nflow.set(\"pingResults\",pingResults);//save pingResults in flow context\n\nmsg.payload = thisPing;\nreturn msg;","outputs":1,"noerr":0,"x":680,"y":260,"wires":[["cf6a929c.6311a"]]},{"id":"90592906.29a578","type":"ui_template","z":"a878aaaa.79a018","group":"3dc35e31.466292","name":"","order":3,"width":"6","height":"5","format":"\n\n","storeOutMessages":true,"fwdInMessages":true,"templateScope":"local","x":840,"y":320,"wires":[[]]},{"id":"71f260f1.aacbf","type":"debug","z":"a878aaaa.79a018","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":590,"y":400,"wires":[]},{"id":"3dc35e31.466292","type":"ui_group","z":"","name":"Default","tab":"5132060d.4cde48","order":1,"disp":true,"width":"6","collapse":false},{"id":"5132060d.4cde48","type":"ui_tab","z":"","name":"Home","icon":"dashboard","disabled":false,"hidden":false}]
```
Result...
---
### Author:  [@lizzardguki](https://discourse.nodered.org/u/lizzardguki)
#### Post date: [4 April 2020 22:57 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/29 "2020-04-04T22:57:36Z")
Check out the new node i just built!
[](https://discourse.nodered.org/t/announce-node-red-contrib-icmp/)
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [3 June 2020 22:57 UTC](https://discourse.nodered.org/t/monitoring-iot-by-ping/23718/30 "2020-06-03T22:57:41Z")
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