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Questions - plc

Writing variables with OPC UA

Recently I was trying to communicate with a Siemens S7-1200 plc, I am using the OPC UA protocol, I am able to connect and read all the variables but I have problems when I try to write a value in the ...
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Gz9812

python

python-3.x

plc

opc-ua

siemens

Votes: 0

Answers: 2

Latest Answer

You use the function set_values which expects a list of nodes. Try this instead: val.set_value(var_2) If the plc returns an error set only the value: val.set_value(DataValue(var_2))
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Schroeder

S7NetPlus plc.Write() not changing cartain values in data block (Siemens S7-1500)

I am using S7.NetPlus library to connect to Siemens S7-1500. When trying to read data from the plc, there are no problems. However, I am having a vary difficult time Writing new values to the plc. I h...
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SeeSharper

c#

asp.net

console-application

plc

siemens

Votes: 0

Answers: 1

Latest Answer

Has this been resolved? I have experienced somewhat similar situation: I am able to write to the (S7-1500 OpenController) PLC but eventually it will stop writing. Or is it the case that the PLC stops ...
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skari

FIFO list using arrays in ST (PLC)

I'm working on a conveyor-sorter solution and need to store data about items in some organised manner. My first guess was FIFO. Do you know if there is any "good practice" way to program eff...
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Kamehameha Pierwszy

fifo

plc

st

Votes: 0

Answers: 1

Latest Answer

I prefer to use Circular FIFO in PLC rather than simple Linear FIFO. The advantage of using Circular FIFO is that it is fast since it doesn't require shifting data. Disadvantage: It requires a little ...
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Rajinder Dua

PLC S7-1500 SQL-Connection - received data shifted by 1 byte --why?

i´ve been successfully using a S7 1500 PLC in combination with an SQL-Server for quiete some time now. I set everything up like mentioned here: S7SQL-Guide-Stackoverflow Today i tried to add a second ...
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nico25

sql

sql-server

plc

siemens

tia-portal

Votes: 0

Answers: 1

Latest Answer

Sometimes weird memory stuff happens when the data type comprises an odd number of bytes. Siemens starts each element on an even memory address. So if Length is at address 0 and Data is at 2-5, then a...
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lcecl

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