Some simple Allen Bradley questions...

Hi

I'm used to programming Siemens stuff but haven't touched AB for a few years now. I've got some simple mods to do to a program at work and wondered if anyone could set me straight on a few things... Firstly, how do the internal bits work? Is it..

I - Input
O - Output
B - Boolean bit (memory register bit)
N - Number? Like a marker word to hold an integer

Any others?

My second question is, does anyone know where I can find a simple run through of stuff like this specific to AB. As I mentioned, I'm up to speed with other PLC systems but just need pointers on AB.

Many thanks

JT ;-)

T -Timers
C - Counters
F -Floats
Etc.

What series of AB PLC are you working with? SLC500, PLC2, PLC5, MicroLogix?

IOBN, yes to all. N is their integer file. F would be for floating point decimal numbers.

If you have a local distributor, I believe they can hook you up with some free labs which should get the ball rolling. The lab handouts are probably available on their website as well, but I have not checked. If you are familiar with other platforms, I would think reading through these labs should get you up to snuff fairly quickly and easily. Good luck.

Russ

S- status bits(not user changeable)

nswu1 said:

S- status bits(not user changeable)

Click to expand...

For the most part as some are user changeable.

http://literature.rockwellautomation.com/idc/groups/public/documents/webassets/browse_category.hcst



Link to manuals.

Obviously select PLC's.

Hi Johnny,
I find myself having to refamilarise with AB for a production line we are inheriting, This link helped me when i was at college:

http://plcguide.mrplc.com/

Have a look at programmming references tab and then half way down the page is the Data types.

Hope this helps

Steve

EDIT: Cant spell

A big thanks for all the info...

Its a SLC 500 PLC out of interest. I've printed out that page you recommended STL?? and will read and digest. I'm just trawling through some of the literature on the rockwell site from PeterW's link.

Cheers

JT ;-)