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The control and information tags created in the folder are:

Name	Type	Description
Last Published File	String	Name of last published file
Last Published Sequence Number	Integer	Sequence number of last published file since last reset of metrics
Percent Completed	Byte	Publish completion percent for file being published
Publish File	Boolean	Manual trigger to publish file
Publish File Count	Long	Number of files published since last reset of metrics
Publish File in Transit	String	Name of current file being published
Publish Files Path	String	Full path to the target file to publish over MQTT
Publish Operation Status	String	Status description of current publish operation
Publish Operation Status Code	Integer	Status code for current publish operation
Reset	Boolean	Trigger to reset publish metrics

At this point, we just need to tell MQTT Transmission which file to send. Download and unzip this sample file to some location and note that location.

This sample_file.zip which contains two text files . The two text files which are:

sample_file.txt
- This is a text file with an arbitrary string. But, it could be a file of any type. This is purely for demonstration purposes.
sample_file.txt.md5
- This is a text file that contains only the md5 sum of the sample_file.txt

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Note

Certain characters have special meanings when used in filenames such as "*" for wildcards, and "\" in filename paths. If a file you are trying to publish contains any of the characters listed below, it will prevent files from being written to the file system.

" * : < > ? / \ |

Leading and trailing spaces in filenames and filenames ending in '.' are also not supported.

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Note

When transferring any file, MQTT Transmission requires two files to be present before it will transfer the target file. The first is the file itself. The second is a file that has the same name as the target file followed by a '.md5' extension.

The contents of that file must contain the Message Digest Algorithm 5 (or MD5 sum) of the file. The MD5 sum can be calculated using command line utilities on most operating systems or through scripting in Ignition. Here are some examples:

Linux

Code Block

language	bash

ubuntu@linux-host:~$ md5sum myfile.bin
07180622a24ebf905cf5f770cd54197a  myfile.bin

# In the above example, the md5 sum is: 07180622a24ebf905cf5f770cd54197a

OSX

Code Block

language	bash

user@osxhost:~$ md5 sample_file.txt
MD5 (sample_file.txt) = 85324ffbcc7d97c478adf53796aff787

# In the above example, the md5 sum is: 85324ffbcc7d97c478adf53796aff787

Windows

Code Block

language	powershell

Get-FileHash -Algorithm MD5 .\some_file.iso

Algorithm       Hash                                                                   Path                                                                              
---------       ----                                                                   ----                                                                              
MD5             80FD169D3FDADBC97E66C168F796B1BF                                       C:\temp\some_file.iso

# In the above example, the md5 sum is: 80FD169D3FDADBC97E66C168F796B1BF

Ignition Script

Code Block

language	py

import hashlib

# File to create md5 sum
file_name = "D:\MyFiles\test_file\test_file.txt"

# Open,close, read file and calculate MD5 on its contents 
with open(file_name, 'rb') as file_to_check:
    # read contents of the file
    data = file_to_check.read()    
    # pipe contents of the file through
    md5_returned = hashlib.md5(data).hexdigest()
    
# Save md5 sum file
f = open(file_name + ".md5", "w")
f.write(md5_returned)
f.close()

With both files in place, we can now set the 'Publish File Path' tag.

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