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Reading Modbus IP
#1
Hi,

I'm currently in a project that is working with modbus IP, I have searched here in the forum and in the examples of the page but I don't see if there is the possibility of using modbus IP.

My question is: can I use Modbus IP with a logic machine and if so, how could I use it?


thank you
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#2
The same way as ModBus RTU - create a profile and assign it to a device.
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#3
(30.10.2019, 13:26)admin Wrote: The same way as ModBus RTU - create a profile and assign it to a device.
Hi,

Thank you very much, now I want to know how the script would be, because for example in modbus RTU one creates a script with the following code:

Code:
-- init modbus on first script execution
if not mb then
     require('luamodbus')
     mb = luamodbus.rtu()
     mb:open('/dev/ttyS2', 9600, 'E', 8, 1, 'H')
     mb:connect()
end

-- sets slave ID to read/write data from/to
mb:setslave(20)

-- read 3-phase system voltage from 32-bit register
r1, r2 = mb:readregisters(0x1000, 2)
result = bit.lshift(r1, 16) + r2
grp.write('5/5/1',result)

for the Modbus IP would I have to change something?

thank you very much
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#4
I suggest using profiles instead of scripts as it provides automatic re-connection and other features. For example, if you create a resident script with your code it will stop working if connection is lost. The only way to make it work again would be to restart the script via disable/enable.

TCP connection is created like this:
Code:
require('luamodbus')
mb = luamodbus.tcp()
mb:open('192.168.0.1', 502)
mb:connect()
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