I learned how to program plc's strictly on Allen Bradley equiptment at my local college. I learned how to use every single instruction and have done quite a few projects including a couple of motion control projects using the SLC platform. I now find myself at a place of employment which does not use A-B equiptment but rather PLCDirect equiptment. I have read all of the instruction manuals and can pretty much write a program without too much trouble.
The thing I am wondering about is the value that is stored in a memory address and manipulating this value. I know that in an A-B programming environment I can see the value in a number of different formats, including decimal, and the math instructions use the decimal format (including constants) which most humans are familiar with. In the PLCDirect environment the closest I can get to seeing a value in decimal format is BCD. I know that over time I will get used to using BCD but why not make it easier on the programmer and include decimal format. The other complaint I have is that I have to constantly load a value I want to manipulate or use into a thing called the accumulator. It just seemed like a lot less instructions to program an Allen Bradley unit compared to the PLCDirect unit.
One of the things I did like about the PLCDirect is the use of states. Even when I wrote programs for A-B platforms I used a state transition approach by latching and unlatching subroutines. PLCDirect makes this task easier by using states.
Will PLCDirect continue to use strictly BCD and continue to make you use an accumulator or do they have plans to change.

 

Have you called PLCDirect for support and started a "debate" with them?

 

As regards to viewing data in decimal format, you can do just that with both the Data View window and with the Memory Editor (you can choose from 4 or 5 different formats). You may find the BCD instruction useful in your programs for convertingyour Hex values. I too found the accumulator loading a necessary evil, but it does force you to think more like a microcontroller programmer, and its had the effect of making my own programs more efficient...AB gives you the flexibility to be more sloppy. AutomationDirect makes a great line of PLCs and I've found no better value for hardware in its range. The on-board support for Modbus is especially useful.

 

"In the PLCDirect environment the closest I can get to seeing a value in decimal format is BCD."

In Directsoft, select Tools, Memory Editor (or <ctrl> Y). In the screen which opens you can select the radix you want.

"The other complaint I have is that I have to constantly load a value I want to manipulate or use into a thing called the accumulator."

Nature of the beast! Wait 'til you see the remote I/O scheme!

"One of the things I did like about the PLCDirect is the use of states. Even when I wrote programs for A-B platforms I used a state transition approach by latching and unlatching subroutines. PLCDirect makes this task easier by using states."

If you like states, you'll really like their drums (sequencers).

 

I agree that the accumulator-centricity takes a little getting used to, but it is a byproduct of the instruction set of the processor in the PLC, which was set long before the PLC Direct guys got ahold of the product.

I think you'll find that each brand of PLC has strengths that make them a good choice for particular types of jobs. It is to your benefit to become familiar with the capabilities of several different brands, because it will make you more useful.

For example, I spent a lot of time on the TI5x0 and 5x5 series more years ago than I care to admit, and am rather partial to their drum instructions for certain applications, and PLC Direct is the only PLC I am aware of which still has one.