topic Re: Connect Thingworx and PLC in ThingWorx Developers

Connect Thingworx and PLC

hshintani1 — Mon, 25 Jan 2016 09:48:57 GMT

Hi,

I'm trying to connect PLC and Thingworx via EMS.

In modbusExample.lua file, defining property for Thing is essential.

I put this property like this,

properties.Int16HoldRegExample = {value="300", dataChangeType="ALWAYS",pushType="ALWAYS", key ="holding_register/1/40001", handler="modbus_handler", basetype="NUMBER"}

But I can't connect.

Which URL does this "key" table mean? PLC ,EMS or Thingworx Composer ?

please let me know information...

Re: Connect Thingworx and PLC

PaiChung — Mon, 25 Jan 2016 18:25:01 GMT

The Modbus example is specifically for connecting using Modbus protocol.

You have a modbus protocol setup to your PLC?

the Key refers to the Modbus register that is to be read.

Re: Connect Thingworx and PLC

hshintani1 — Tue, 26 Jan 2016 01:41:29 GMT

I use Modbus package and set up modbus protocol to my PLC.

Is it ok that only modbus register is included in key contents,for example key = "40001" ?

Re: Connect Thingworx and PLC

PaiChung — Tue, 26 Jan 2016 14:27:16 GMT

Unfortunately I'm not too familiar with how the modbus.lua is setup and how it processes the key that is put in.

Hopefully someone else can give some input on that.

Re: Connect Thingworx and PLC

tcoufal — Wed, 27 Jan 2016 11:06:24 GMT

First of all you need to make sure that your Modbus communication is working properly.

That deppends on type of connecten. Are you using Modbus over serial - i.e. RTU/ASCII over RS485? or Modbus over TCP??

You can try program like Modbus Poll to verify your settings and readings. That's what I am using. (it's only a 10minutes demo though).

Then you need to change your config.lua file accordingly. Regarding reading the registers, I think that you need to define a type as well.

This is what I am using (just an example):

properties.VoltageVan = {key="input_register/1/30002?format=Float", handler="modbus_handler1", basetype="NUMBER"}

Its always good idea to use some network protocol analyzer (Wireshark is the best no doubt) when dealing with low-layer communication.

--> Tomas

Re: Connect Thingworx and PLC

hshintani1 — Tue, 02 Feb 2016 05:08:32 GMT

Thanks for your information.

I'm using Modbus over TCP protocol. And I could read holding register data from PLC with holding_register function in modbus_handler.lua.

But,I can't write data from ThingWorx to PLC via EMS.The cause is timeout like this:

[ERROR] 2016-02-01 17:17:39,410 modbus:executeFunction: Error: Timed out waiting for result.

[ERROR] 2016-02-01 17:17:39,410 luaInterscriptBinding::l_executeCallback: Error executing callback 'modbus_handler//scripts/modbus_handler/holding_register/1/40001'

Returned: 500 Timeout

[WARN ] 2016-02-01 17:17:39,411 MyPLC: Could not write property: Int16HoldRegExample, code: 500, msg: Timeout

Does the holding_register function include not only reading holging_register value but writing the same holding_register value?

Or should I set something else for writing property ? If you know,please teach me...

Re: Connect Thingworx and PLC

PaiChung — Tue, 02 Feb 2016 18:47:49 GMT

Holding Registers should be able to be read and written to.

What function are you using for the write?

Re: Connect Thingworx and PLC

tcoufal — Tue, 02 Feb 2016 21:33:30 GMT

I would be interested in that function as well.

What kind of PLC system are you using? Systems which I am familiar with needs a proper configuration in a project in the first place to allow MODBUS registers (coils and holding registers) to be written into. It is a safety issue. Use Wireshark to capture Modbus packets sent and recieved from/by your lua script. That could give you some clue.

Re: Connect Thingworx and PLC

Aanjan — Tue, 02 Feb 2016 21:34:21 GMT

Can you post the property string you're using in your modbus template.lua file?

Re: Connect Thingworx and PLC

hshintani1 — Wed, 03 Feb 2016 02:06:42 GMT

This line is for setting property.

properties.Int16HoldRegExample = {value="300", dataChangeType="ALWAYS",pushType="ALWAYS", key ="holding_register/1/40001?format=Int16", handler="modbus_handler", basetype="NUMBER"}

And,these line are for setting services to get property value.

services.getAllProperties = function(me, headers, query, data)

log.debug(me.name, "Called getProperties")

local postdata = {content='{"slave": 1 ,"address": 40001 , "count": 1, "data": "string"}'}

return tw_script.executeCallback("modbus_handler", "POST", "holding_register", headers, query, postdata)

Re: Connect Thingworx and PLC

jcanosa — Sat, 06 Feb 2016 21:46:40 GMT

You can try adjusting the timeout value in config.lua

You can do so in the section

scripts.modbus_handler = {

file = "modbus_handler.lua" ,

response_timeout = 10000,

}

Not that the number is in milliseconds. The default is 5000.

You can also debug your connection by talking directly to the modbus_handler script itself. On the machine that your EMS is running, point a browser with your favorite REST debugging tool, like Postman, to http://127.0.0.1:<port>/scripts/modbus_handler/holding_register/<slave_id>/<register>

where port is the port your Lua Script resource is listening on - defaults to 8001, slave_id would be 1, and holding_holding register would be 4001 in your case.

For writing you should be should be doing a PUT to /holding_register/<slave_id>/<register>

Take a look at the documentation in /etc/thingworx/scripts/modbus_handler.lua for some more details on how to interact directly with that script.

Re: Connect Thingworx and PLC

pkeckes — Wed, 27 Apr 2016 08:55:25 GMT

Hi John, how exactly work this service.getAllProperties in modbusExample.lua? I can't see this service in remote thing for binding (how I can call it?). Also I having issue to read coils and discrete inputs - as bit values and using workaround with Uint16 word value - It's working, but it's not right. Could you please advice? Thanks.

Re: Connect Thingworx and PLC

jcanosa — Wed, 27 Apr 2016 15:20:55 GMT

Peter - In looking at the modbusExample.lua file that you posted (I assume this is the one you are referring to), I don't see a service definition in that template. That is why you don't see it when you browse from Composer. If I remember right read_multiple_registers returns a string with a comma separated list of formatted values. You can double check this by directly POSTing to the modbus_handler script to see what comes back.

A coil property definition should look like the following:

properties.CoilTest1 = {key="coil/<slave_id>/<coil_number>", handler="modbus_handler", basetype="BOOLEAN"}

One thing to be careful of is offset in modbus addressing. Depending on your modbus slave the first coil might be coil #1 at address 0 which is typical or they might call it by its address (i.e. coil 1 is at address 1 and coil 0 is at address 0).

Re: Connect Thingworx and PLC

echo — Thu, 12 May 2016 13:28:23 GMT

Hi,

I also facing problem on connecting IDEC to ThingWorx.

below is the result after I run ./luascriptresources

[ERROR] 2016-04-09 11:34:20,113 luaScriptProxy::execute: [1094014096] Error executing script modbus_handler, Error = Error: ...t/thingworx/MicroServer/etc/thingworx/lua/modbus.lua:104: module 'socket' not found:

no field package.preload['socket']

no file '/opt/thingworx/MicroServer/etc/socket.lua'

no file '/opt/thingworx/MicroServer/etc/thingworx/socket.lua'

no file '/opt/thingworx/MicroServer/etc/thingworx/lua/socket.lua'

no file '/opt/thingworx/MicroServer/etc/custom/socket.lua'

no file '/opt/thingworx/MicroServer/etc/custom/lua/socket.lua'

no file '/opt/thingworx/MicroServer/etc/community/lua/socket.lua'

no file './socket.lua'

no file '/usr/local/share/lua/5.1/socket.lua'

no file '/usr/local/share/lua/5.1/socket/init.lua'

no file '/usr/local/lib/lua/5.1/socket.lua'

no file '/usr/local/lib/lua/5.1/socket/init.lua'

no file '/opt/thingworx/MicroServer/etc/thingworx/clibs/socket.so'

no file '/opt/thingworx/MicroServer/etc/custom/clibs/socket.so'

no file '/opt/thingworx/MicroServer/etc/community/clibs/socket.so'

no file './socket.so'

no file '/usr/local/lib/lua/5.1/socket.so'

no file '/usr/local/lib/lua/5.1/loadall.so'

[ERROR] 2016-04-09 11:34:20,118 luaScriptProxy::app_unlock: [1094014096] Attempt to unlock app_mutex while not holding it.L= 0x1141f0

hope someone can help.

thanks in advance

Re: Connect Thingworx and PLC

Aanjan — Thu, 12 May 2016 13:57:22 GMT

Eric, what version of the MicroServer are you using? Do you have the Modbus package with it as well?

Re: Connect Thingworx and PLC

pkeckes — Thu, 12 May 2016 14:02:41 GMT

Hi Eric, looks like you using latest 5.1 version - you need Modbus complete Modbus package - is missing - If you would like to download my package and search or socket.lua (and other files if needed) and add them to your microserver / or reuse my package with your config files (config.lua and config.json).

Re: Connect Thingworx and PLC

pkeckes — Thu, 12 May 2016 14:04:07 GMT

Have in mind - I'm using version 5.3.1.1113 with some changes to get it work

Re: Connect Thingworx and PLC

echo — Thu, 12 May 2016 15:38:26 GMT

Hi,

Thanks for your fast reply. Sorry that i am very new to Thingworx.

How to check the version? The modbus package is that something like mobusscript.lua?

Fyi, i had actually downloaded the EMS to Syslink Systech SL-3000.

Re: Connect Thingworx and PLC

Aanjan — Thu, 12 May 2016 17:17:38 GMT

Here's a link to a quick start Modbus blog that has downloads to the package as well.

Re: Connect Thingworx and PLC

echo — Fri, 13 May 2016 02:40:46 GMT

Thanks everyone.

Question to Peter, may I know where to get the complete Modbus package?

Can I use this package?

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