# Errors loading modbus nodes on RevPi

**URL:** https://discourse.nodered.org/t/errors-loading-modbus-nodes-on-revpi/10156
**Category:** General
**Created:** [15 April 2019 09:25 UTC](https://discourse.nodered.org/t/errors-loading-modbus-nodes-on-revpi/10156 "2019-04-15T09:25:46Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![stgv](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@stgv](https://discourse.nodered.org/u/stgv)
#### Post date: [15 April 2019 09:25 UTC](https://discourse.nodered.org/t/errors-loading-modbus-nodes-on-revpi/10156/1 "2019-04-15T09:25:46Z")

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Since my company considers using the [Revolution Pi Connect](https://revolution.kunbus.com/revpi-connect/) in the future, I tried deploying our current flow on this hardware.

I've set up Node-RED by following the steps outlined in the [installation guide](https://nodered.org/docs/hardware/raspberrypi), then loaded our project (after adjusting the settings file accordingly, of course) and installed the dependencies following Node-RED's complaints. Among these dependencies is the Modbus package, which installs, but keeps some nodes, notably flex-getters (which are used, among others, in our flow) disabled. I get some warnings displayed in the browser, but the node-red-log seems clean.

Running my browser from a terminal, I get the following:

```auto
** Message: console message: http://localhost:1880/red/red.min.js @16: Node-RED: 0.20.5
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Client] SyntaxError: Unexpected identifier 'node'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Read] SyntaxError: Unexpected identifier 'nodeLabel'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Getter] SyntaxError: Unexpected identifier 'tabs'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Flex-Getter] SyntaxError: Unexpected identifier 'tabs'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Write] SyntaxError: Unexpected identifier 'previous'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Flex-Server] SyntaxError: Unexpected identifier 'node'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-modbus/Modbus-Response-Filter] SyntaxError: Unexpected identifier 'node'
** Message: console message: http://localhost:1880/red/red.min.js @16: [node-red-contrib-play-audio/play-audio] SyntaxError: Unexpected token ')'

```

which matches with the warnings that get shown in the Node-RED UI. I did not get these on a regular Raspberry Pi and a Windows machine.

Any clue what the problem could be here? Could it have to do with the RevPi using a modified Raspian version with RT kernel? Or is it perhaps only a browser problem (I'm ssh-ing into the machine and inspect the flow locally in Epiphany, because at the moment there are no other browsers installed)?

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### Author: ![stgv](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@stgv](https://discourse.nodered.org/u/stgv)
#### Post date: [15 April 2019 10:35 UTC](https://discourse.nodered.org/t/errors-loading-modbus-nodes-on-revpi/10156/2 "2019-04-15T10:35:25Z")

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Hm, seems to be a problem with Epiphany's JavaScript engine indeed. All works fine if I use Firefox (except Firefox itself, because its hunger for resources is apparently too much for the RevPi...)

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### Author: ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [15 April 2019 16:34 UTC](https://discourse.nodered.org/t/errors-loading-modbus-nodes-on-revpi/10156/3 "2019-04-15T16:34:51Z")

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can you not point a browser from (say) a laptop at it instead ? no need to ssh in ... so the browser is then running on a more capable device.

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### Author: ![stgv](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@stgv](https://discourse.nodered.org/u/stgv)
#### Post date: [16 April 2019 06:58 UTC](https://discourse.nodered.org/t/errors-loading-modbus-nodes-on-revpi/10156/4 "2019-04-16T06:58:50Z")

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That's what I would like to do, but is (at least to my knowledge) unfortunately not compatible with OAuth callbacks (I use passport-gitlab for authentication on the system) unless every device running Node-RED eventually has its own URL which would also need to be known (i.e. most likely hard-coded somewhere) to the system whenever Node-RED is started - so that it can be filled in when the settings.js are read. Not to mention that this would also require a potentially very large URL whitelist on the Gitlab side of things for the callback mechanism.  
Because we don't have URLs for all our individual devices, the only short-term feasible solution I could come up with was to set the callbacks to localhost:1880, but that then requires also the browser to be executed on the device, because localhost would otherwise not be the machine to which routing needs to go back after authentication.
