Connect Thingworx and PLC

[hshintani1]

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...

[PaiChung · Accepted solution]

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.

[hshintani1]

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" ?

[PaiChung]

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.

[tcoufal]

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

[hshintani1]

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...

[PaiChung]

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

What function are you using for the write?

[tcoufal]

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.   

[Aanjan]

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

[hshintani1]

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)

[jcanosa]

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.

[pkeckes]

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.

[jcanosa]

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).

[echo]

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

[Aanjan]

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

[echo]

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.

[Aanjan]

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

[pkeckes]

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).

[pkeckes]

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

[echo]

Thanks everyone.

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

Can I use this package?

Content

[pkeckes]

Click on my name and that will lead you to my profile page - there is attached zip file Microserver 5.3.1 Modbus example. The package you pointing is TWEMS is the example package I originally used, but it need a bit of configuration to get it work. There are also some issues with coils and discrete inputs as it was designed for TWEMS and not current WSEMS Microserver. I have some workaround in my Modbus example package. Compare them and use them as source examples for your project.

[echo]

Thank you Peter,

I had re-download the EMS with Modbus package to my device, and got this error.

root@SL3000-1191D6:/opt/thingworx/MicroServer# ./luaScriptResource
[INFO ] 2016-04-08 12:52:59,244 ./luaScriptResource: Using config file: /opt/thingworx/MicroServer/etc/config.lua
[FORCE] 2016-04-08 12:52:59,253 ./luaScriptResource: Starting up ....

[TRACE] 2016-04-08 12:52:59,282 luaConfigurator::doGetItem: Global property or script log_level not found
[TRACE] 2016-04-08 12:52:59,284 luaConfigurator::doGetItem: Global property or script rap_host not found
[TRACE] 2016-04-08 12:52:59,287 luaConfigurator::doGetItem: Global property or script rap_host not found
[TRACE] 2016-04-08 12:52:59,291 luaConfigurator::doGetItem: Global property or script rap_host not found
[TRACE] 2016-04-08 12:52:59,293 luaConfigurator::doGetItem: Global property or script rap_host not found
[TRACE] 2016-04-08 12:52:59,294 luaConfigurator::doGetItem: Global property or script rap_port not found
[TRACE] 2016-04-08 12:52:59,295 luaConfigurator::doGetItem: Global property or script rap_port not found
[TRACE] 2016-04-08 12:52:59,296 luaConfigurator::doGetItem: Global property or script rap_port not found
[TRACE] 2016-04-08 12:52:59,297 luaConfigurator::doGetItem: Global property or script rap_port not found
[TRACE] 2016-04-08 12:52:59,299 luaConfigurator::doGetItem: Global property or script rap_ssl not found
[TRACE] 2016-04-08 12:52:59,299 luaConfigurator::doGetItem: Global property or script rap_ssl not found
....

[DEBUG] 2016-04-08 12:52:59,375 ./luaScriptResource: Appending /opt/thingworx/MicroServer/etc/thingworx/clibs;/opt/thingworx/MicroServer/etc/custom/clibs;/opt/thingworx/MicroServer/etc/community/clibs to current path /usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin
[INFO ] 2016-04-08 12:52:59,376 ./luaScriptResource: New path is /opt/thingworx/MicroServer/etc/thingworx/clibs:/opt/thingworx/MicroServer/etc/custom/clibs:/opt/thingworx/MicroServer/etc/community/clibs:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin
....
[DEBUG] 2016-04-08 12:52:59,515 luaScriptProxy::initialize: Name = modbus_handler

File = /opt/thingworx/MicroServer/etc/thingworx/scripts/modbus_handler.lua

LibraryPath = /opt/thingworx/MicroServer/etc/?.lua;/opt/thingworx/MicroServer/etc/thingworx/?.lua;/opt/thingworx/MicroServer/etc/thingworx/lua/?.lua;/opt/thingworx/MicroServer/etc/custom/?.lua;/opt/thingworx/MicroServer/etc/custom/lua/?.lua;/opt/thingworx/MicroServer/etc/community/lua/?.lua
InitData Ptr = 0

Persisted Props:
file = modbus_handler.lua
host = 128.100.20.49
name = modbus_handler

GlobalProps:
config_file_path = /opt/thingworx/MicroServer/etc
keepAliveRate = 6000
log_level = TRACE
rap_host = localhost
rap_port = 8000
script_clib_path = /opt/thingworx/MicroServer/etc/thingworx/clibs/?.so;/opt/thingworx/MicroServer/etc/custom/clibs/?.so;/opt/thingworx/MicroServer/etc/community/clibs/?.so
script_directory = /opt/thingworx/MicroServer/etc/custom/scripts
script_library_path = /opt/thingworx/MicroServer/etc/?.lua;/opt/thingworx/MicroServer/etc/thingworx/?.lua;/opt/thingworx/MicroServer/etc/thingworx/lua/?.lua;/opt/thingworx/MicroServer/etc/custom/?.lua;/opt/thingworx/MicroServer/etc/custom/lua/?.lua;/opt/thingworx/MicroServer/etc/community/lua/?.lua
script_resource_host = 127.0.0.1
script_resource_port = 80

[DEBUG] 2016-04-08 12:52:59,607 luaScriptProxy::runScript: Starting Script
[TRACE] 2016-04-08 12:52:59,613 luaConfigurator::doGetItem: Global property or script modbus_handler not found

hope you can help. thank you