9/25/2019 3:36 PM | |
Joined: 3/27/2017 Last visit: 7/11/2024 Posts: 54 Rating: (0) |
Thank you a lot Mr. Ahmad
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Last edited by: CS Moderator at: 09/25/2019 17:02:28New subject after import; Reference added |
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9/29/2019 11:06 AM | |
Joined: 5/28/2008 Last visit: 10/12/2024 Posts: 4515 Rating: (839)
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Hello, Let me explain my point of view in my post you reffered to. Analog value is reppresented in a word (two bytes). Example (IW 128) is represented in bytes 128 & 129. To understand resolution issue, you should know or remember that changes of physical quantaties you are measuring using transducer (i.e level, flow, pressure ,..etc) is being represented and changes in an electrial value in some standard ranges like ( (0-10V), 4-20mA) ,...etc) The mission of analog Input modules is to take these electrical value and tell the CPU the analog input is now equal to : x for instance. It done using ADC (Analog to digital Converter). But not each changes (small or big) happen in the physical value the transmitter measures can be known by the CPU. it depends on the AI module and the change itself Examples
Now see the attached picture. you will found that each analog value is represented in two bytes (high byte & low byte). Always, low byte is written in the right hand side and high byte is written in left hand side. The misunderstanding is comming from the meanining of low / high bytes. Low byte contains bit No. 0, 1, 2 ,. ...7 which is MB1 in your example "MW0" Please see the next post attachment. |
Ayman Elotaify |
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9/29/2019 11:07 AM | |
Joined: 5/28/2008 Last visit: 10/12/2024 Posts: 4515 Rating: (839)
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Attachment 2 |
Ayman Elotaify |
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