RS Logix 500 - Input section - FW and W

Is it safe to assume any channel with 'W' has potential current coming into it? For example, since 5.2 and 5.3 don't have 'W', then there are no devices hooked up into those channels?
 
"W" means used at the WORD level ... for an example - look for something like a MOV (Move) command referencing this address ...

"F" means used at the FILE level ... for an example - look for something like a COP (Copy) command referencing this address ...

"USED" in this sense means that the CODE/PROGRAM/LOGIC/LADDER is making use of the address ... it has NOTHING to do with whether the address has something/anything (such as a device in the field) "wired up to it" ...

here's an old link that might be helpful ...

http://www.plctalk.net/qanda/showthread.php?p=419243&postcount=10

good luck with your project ...
 
Last edited:
I am 100% positive I am using a 4-20 mA signal on 4.0, 4.1, 4.2, 4.3, 5.0, and 5.1, as I am using these in SUB instructions, so unsure why it is not showing up as "used". Probably some fault in the software. This is why I thought maybe since there is no W next to 5.2 and 5.3, those channels are more than likely open. There is slim chance something is actually plugged in, since there is no logic for those in the plc program.
 
if you can post your ENTIRE program file (RSS extension) - then we can probably give you more detailed help ...

just ZIP the file first (forum rule) and attach it to this thread ... there are some of us "old-timers" here who will NOT access "dropboxes" etc. ...
 
I just needed to figure out an easy way to guess whether or not the channel is used on the card or not. The W is what I am looking for and all I needed. Thanks for the help ! The 'usage' issue isn't a big deal, I can cross-reference or look at the "W'"
 

Similar Topics

Hi All, I would like to ask you if possible to have some samples code for the realization of a software filter to be used in a PLC Micrologix...
Replies
2
Views
2,026
Good Day. I wrote a program to check if ten input sensor conditions were met. The program works fine and if all the input conditions are met the...
Replies
18
Views
4,170
I need to pass variables to and from a 3rd party controller that supports EthernetIP. The machine I need to install it on has a SLC5/05 and I...
Replies
2
Views
3,086
Hi all, I have a 1769-IF8 Analog Input Card in a Micrologix 1500 system. The card does not read any inputs. I already checked the wiring and it...
Replies
5
Views
5,976
I may be being think here, but could someone explain how the "Input Latch Enable" works. Not familar with this range. The help says "Input Latch...
Replies
1
Views
3,075
Back
Top Bottom