To Upload or To Download

The way it was explained to me was as follows:
The device with the greatest amount of computing power in a PLC/PC connection is the PC, so when I transfer a file to PC from PLC I am uploading. If I take that same PC and instead go onto the web, the combined total computing power that I am accessing is greater than my laptop or PC. So when I access a file I am downloading from the more intelligent or more powerful computing source. When I am connected to a PLC (even a small PLC network) my PC is considered to be more powerful/intelligent and I am downloading to the less powerful PLC.
 
Mike,
Uploading has always been to send a file and downloading has always meant to retrieve a file from a remote computer
No so! Perhaps you have not been on this earth long enough to remember! PLCs have been around longer than other computers, except mainframe computers. On an IBM 360 mainframe, when I learned programming back in the 1960's, upload meant to put data into memory, and download meant to move data from memory. Is not this exactly the same for most PLC Programming Devices (Personal Computers), when you put your mind INSIDE the Computer, not the PLC connected to it)?

Your error is in your perspective, your orientation. An "upload" to (inside) the PLC is a "download" for a computer connected to the PLC. You seem to be viewing the world FROM THE PLCs viewpoint, not the computer connected to it.

The early PLCs did not even have a device to connect to, so there was not much use to "download data" from the PLC to the programming breadboard (or later, the handheld device). The focus was in "downloading" (moving the data FROM) from the programming device into the PLC. This is exactly as RSLogix works.

I think the meaning was really twisted when PC networks (bulletin boards) became popular. Then, the "download" from the server got treated (by many users-not this one!) also as a "download" into the PC, but actually the original meaning was: as the data "downloaded" (from the main server viewpoint) and left the main server, it was at the same time an "upload" for the PC, from the PC viewpoint.

The meaning of up and down depends on where you are standing. Here is a quick tip to prevent confusion: Data, just like ****, flows DOWNhill from a computer. To get it back in, it must go UP (DOWNLOAD TO another place, but UPLOAD FROM another place).
 
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Sliver said:
The way I remember is I picture setting the laptop on top of the PLC

Brian.

Made me laugh that post because that is exactly what I do too.

It all stemmed from me having to 'download' a lot of parameters from an inverter keypad into about thirty different inverters. I plugged in the keypad to the first and chose 'upload'. I was used to PLC's and automatically assumed that I had put parameters into the keypad so was 'uploading' them to the inverter... wrong!

After that I always pictured the keypad on top of the inverter and correctly picked 'download' to transfer the parameters.

Panicmode's post on the page 2 of this thread is probably the best explaination I've read on the subject.

I think it was the old Omron software that used to just use 'transfer to PLC' and 'transfer from PLC'. That seemed to me a better way of describing the actions to someone who was unsure...

;-)
 
It would be best not to ASSUME meanings that UPLOAD and DOWNLOAD do not have.
DOWNLOAD2.JPG
 
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Lancie1 said:
It would be best not to ASSUME meanings that UPLOAD and DOWNLOAD do not have.
DOWNLOAD2.JPG


In your first diagram you could also say:
Device 1 is uploading data to Device 2
Device 2 is downloading data from Device 1

In the second diagram you could also say:
Device 1 is downloading data from Device 2
Device 2 is uploading data to Device 1
 
Lancie1 said:
It would be best not to ASSUME meanings that UPLOAD and DOWNLOAD do not have.

Hmmm...It seems like I've touched a nerve with a few of you.

I didn't just get a 'puter from my parents a few years ago. I've been doing this for a while. Not as long as some of you but my first exposure to the "pc" was apple II and commodore 64. I'm also a computer history buff. The term upload and download used today goes back at least as far as the fist modems from Bell Telephone Company.

To make it clear that I didn't assume anything ( and we all know what *** U ME does =]).

I figure some of you don't put much stock in wikipedia so here is some more links :

A similar discussion from 1994

A difinition

Another Definition

And one more with a link to Jargon File

Now one for you guys

The last one talks about is about PLCs and uses the terms in the way that you all are accostumed to. But there is some interesting historical references here.

Perhaps "backwards" was a poor choice of words on my part. I should have said opposite.

The relationship of the person performing the action is very much an important part of todays ( and yesterdays, but not the day before yesterdays ) definiton of upload/download.

This reminds me of the whole kilobyte/kibibyte fiasco on slashdot a while back. No one wanted to accept that a kilobyte is now 1000 bytes and not 1024 bytes ( unless talking about computer memory...talk about "standards") I was one who resisted until I actually looked it up. The whole concept of byte quantities changed for me in half a day. For some it changed in 1998 when the standard was set by IEEE.

So...I'll download programs to my plc and upload programs to my server. Unless I use one of the sytems talked about earlier in this thread where its the other way around. ( talk about "standards" ).

I would like to thank you all for your input. It's been an interesting conversation.


Mike
 
Paulus said:
As far as 'backwards' when talking about PLCs, programs were being uploaded and downloaded to PLCs (in the fashion described)long before such things as the WWW or FTP servers and the like even existed.

Sorry to nitpick, but FTP has been around since about '72 or '73 and the orgins of the internet date back to 1962 with MIT's 'Interglactic Network'. The idea to network computers has orgins as far back as the 40's when some researcher or another used a teletype to control and receive results from from a computer miles and miles away.

GM didn't request it's 'electronic replacement' of old hardwired relay systems (i.e. the first PLC) till 1968. I'm not sure when that contract was fulfilled. My guess is '69 or later. Not to mention that programming PLC's really wasn't associatied with uploading and downloading from a PC till the 80's as far as I know. Wasn't it pretty much a hand held affair before that?

So I kinda have to agree that most PLC manufacturer's represent the upload/download 'backwards', unless you think of it from the PLC's perspective.
 
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So I kinda have to agree that most PLC manufacturer's represent the upload/download 'backwards', unless you think of it from the PLC's perspective.
Technically most do not use the term download and upload.

This reminds me of the whole kilobyte/kibibyte fiasco on slashdot a while back. No one wanted to accept that a kilobyte is now 1000 bytes and not 1024 bytes ( unless talking about computer memory...talk about "standards") I was one who resisted until I actually looked it up. The whole concept of byte quantities changed for me in half a day. For some it changed in 1998 when the standard was set by IEEE.

Far as I know there was never an actual fiasco, the terms are relative to the "base" system being used...ie

In decimal systems, kilo stands for 1,000, but in binary, a kilo is 1,024 (2 to the 10th power). Technically, therefore, a kilobyte is 1,024 bytes, but it is often used loosely as a synonym for 1,000 bytes. For example, a computer that has 256K memory can store approximately 256,000 bytes in memory at one time.

To distinguish between a decimal K (1,000) and a binary K (1,024), the IEEE has suggested following the convention of using a small k for a decimal kilo and a capital K for a binary kilo, but this convention is by no means strictly followed.

I have no idea what a kibibyte is.
 
rsdoran said:
Far as I know there was never an actual fiasco, the terms are relative to the "base" system being used...ie

Heh...thats because you weren't in on THAT conversation. Believe me it got pretty heated.

rsdoran said:
In decimal systems, kilo stands for 1,000, but in binary, a kilo is 1,024 (2 to the 10th power). Technically, therefore, a kilobyte is 1,024 bytes, but it is often used loosely as a synonym for 1,000 bytes. For example, a computer that has 256K memory can store approximately 256,000 bytes in memory at one time.

It used to be that way. But no longer. Actually I think this caused more confusion after it was changed, but many disagree with me. I really don't think that the non-programmer needs to know such things and the change was ludicrous to me. But thats just me.

rsdoran said:
To distinguish between a decimal K (1,000) and a binary K (1,024), the IEEE has suggested following the convention of using a small k for a decimal kilo and a capital K for a binary kilo, but this convention is by no means strictly followed.

I'm sorry. It was the IEC not the IEEE (though i think they were involved). As it was pointed out by a few slashdotters, K is Kelvin and k is kilo. To avoid confusion Ki is now used to denote 1024 and k is 1000( as it always has been).

KiB = Kibibyte = 1024 bytes.

rsdoran said:
I have no idea what a kibibyte is.

A kibibyte is 1024 bytes. You can find information on it here. I didn't see it on this page, but I believe that this isn't so when talking about computer memory so it won't affect the way we think about PLCs.

My point is that things are not always what they used to be. Electricity was once thought to flow from positive to negative. Because it wasn't changed when it was discovered to be incorrect ( people naturally resist change ), we are now stuck with hole flow.
 
Lancie1 said:
No so! Perhaps you have not been on this earth long enough to remember! PLCs have been around longer than other computers, except mainframe computers.

Eh... the PDP-1, which is as far as I know the first 'Mini-computer' was around by 1962. PLC's were almost a decade into the what is now recognized as the 3rd generation of computing.

I can't believe you used a 360 series. I've heard they were a nightmare, despite being groundbreaking in some of the computing concepts IBM introduced with them. I wonder if they're are still any of them in service.
 
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Steve Bailey said:
Maybe when we're finished with the "correct" direction for uploads and downloads we can get around to settling the question of how many angels can dance on the head of a pin...

...or how many licks it takes to get to the Tootsie Roll center of a Tootsie Pop.
 
Steve Bailey said:
Maybe when we're finished with the "correct" direction for uploads and downloads we can get around to settling the question of how many angels can dance on the head of a pin...

Some people would say none because they dont exist, some people would say they dont know if they exist, and then some people would say an infinate number, and others would tell you exactly how many. Acutally thou I havent pondered the question that much, its just the answers that I wonder about....
 

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