Function Block Diagram Programing

[fbeduhn]

First time on:
I need to program a couple of AB ControlLogix 5550 PLC's with (FBD) function block diagram programs/. I have never programed a ControlLogix let alone in FBD. Help...Where can I learn to program FBD, fast?

Witch FBD you don't understand?

You can learn about many of FBD in the help of RS5000 software.

click Help, choose instruction help and choose the function block you want learn

[Gerry]

If you have mathematical functions to implement or advanced loop control, then FBD offers some very powerful features. On the other hand, if you're doing AND - OR logic and sequencing, I'd say forget it except as an academic exercise and stick to ladder. The diagrams can very quickly get large and unwieldy for only minor functionality.

The last time I checked, there was no on-line editing capability for FBD's.

[kkgo]

I strongly suggest that if you do not have any experience with the ControlLogix (Or any of the Logix based processors)
You should go through the basic first. Many people made the mistake of assuming the ControlLogix has the same memory structures, ladder scan cycle, etc... as the PLC5/SLC500... but it is a totally different animal altogether.
For example...
... There will be a limitation on their "connections" to I/O modules, depending if it is an Analog, Diagnostic, optimized rack, etc.
... There is a feature in RSLinx that will optimized your OPC packets, and if you start editing the tags on line (e.g. changing from BIN to INT) You will probably get into trouble.
... It's best to use Arrays and the "User Defined Tags" to lower the comms between your PLC and MMI...

I can't list them all down, (Or even remember them all...) But there is a RSLinx/ControlLogix optimization tips document, that AB would suggest you read through... I don't think that reading through it is an option. I think you must look through it before you start you program. (I can't remember the document name. But the sales guy that serve you should know it... I hope))