Replacing Omron With Allen Bradley

[mdeltat]

My Omron CPM1A-40CDR-A with CPM1-20EDR expansion has officially died. The program has also been lost. Therefore, this seems an opportune time to switch to an Allen Bradley solution since the rest of the plant uses AB products. Any suggestions for a replacement. What considerations should be made when making this change. Thanks.

 

[zankorel]

The main initial consideration is how much/what sort of IO is required, as well as what interfaces do you need, ie ethernet or RS232/modbus etc.

 

[mdeltat]

240VAC Power Supply. 24 DC input and 16 TR/RY output

 

[zankorel]

Id put in a Compactlogix, probably a L32E, with appropriate IO modules.

 

[mdeltat]

What do you think about a micrologix 1200 1762 L40 BWA?

 

[zankorel]

I havent used a 1200, but in general Micrologix's are good value for money if cost is a big issue. However, i tend to find Logix500 software restrictive and prefer to use Logix5000.

Id also recommend a 1100 over the 1200 solely for the inbuilt Ethernet port.

 

[mdeltat]

OK Thank you for helping out with this.

 

[TConnolly]

For the IO count look at the new ML1400 over the ML1100. It has more IO on the base unit and supports more expansion modules, but also has e-net and online programming support.

http://literature.rockwellautomation.com/idc/groups/literature/documents/pp/1766-pp001_-en-p.pdf

If you have a hard copy of the original Omron program than I suggest you define symbols to represent the Omron addresses, eg define _10_01 as a symbol for 10.01 with the appropriate new AB address, and then enter your program using the symbols. After its entered you can go back and rename the symbols to something meaningful and re-import to overwrite with the new names.

In this post http://www.plctalk.net/qanda/showpost.php?p=162304&postcount=5 I attached a spreadsheet template for creating symbols and descriptions quickly in Excel and then importing them into RSLogix500.

If you need help interpreting some of the Omron instructions then get back here and ask.

 

[mdeltat]

OK I need help interpresting some of the Omron symbls etc.

First - What would be the AB equivalent of the way a clock pulse bit 255.02 is used to increment a counter here?

Second - In rung 5, how is 200.00 and 200.01 being used here? And, why are they addressed to "200" specifically? Would the AB equivalent be a latch? Also, why is there an extra vertical line in the instruction symbol?

Third - Thank you for your help.

 

[RoTaTech]

255.02 is the built-in 1 second timer pulse. (ON one second, OFF one second)

You could either program two T4 timers to toggle every 1 second, or if the time is not critical, use a built in S2 Free-Running Clock bit in the identical manner as 255.05 to get 0.64 or 1.28 seconds.

200.01 is being used as the output coil after a one-shot (OSR or ONS). DIFU is DiferentiateUp, or OneShotRising.

In rung 5, the extra vertical indicates the bit is derived from a DIFU instruction. Were it on the right side of the contact, it would be from a DIFDown.

The KEEP instruction for bit 200.00 is identical to a SET/RESET latch. The upper branch Sets the bit, the lower RESets it.

200 is a word of 16 bits. Just as you may pick B3:1 for some group of related bits; the original programmer picked 200 for his/hers. Likely because it's a nice round number, nothing more. Omron does not have dedicated memory areas for Words and Bits, they are from the same pool of CIO memory. They are referred to as channels.

You have inputs in channels (words) 0 and 1, and outputs in channels 10 and 11.

I myself try to avoid the lower words, 100 to 199, as these are the areas where real IO is mapped on some PC models. That way my programs can be ported among Omron models with no change (except where the outputs _are_ in the 100 area instead of the 10 area.)

And before you ask, the TIM004, etc. contacts, are equivalent to A-B T4:x.DN bits. And note that Omron timer presets are in tenths (0.10) seconds, whereas A-B are in seconds or jiffies. (yes, a jiffy is a unit of time - look it up!)
RT

 

[TConnolly]

To get a timer equivalent to 255.02 create any T4:X timer with a one second time base and a preset of 32767. The least significant bit of the accumulaotr, T4:X.ACC/0 will be on for one second and off for one second. In a branch right after the timer unconditionally unlatch T4:X.ACC/14. The timer will never time out and will not need to be reset.

SOR BST T4:255 1.0 32767 0 NXB OTU T4:255.ACC/14 BND EOR

 

[mdeltat]

I greatly appreciate your valuable insight and teaching. This is the AB version. Could you proof it for me? My areas of concern are the translation of the KEEP and DIFU instructions as well as my execution of your timer suggestion. Also, did I get my timer presets right? Thank you very much for taking the time to coach me.

 

[gtsuport]

Sorry Guys!!

255.02 is a one second clock pulse, but it is on for 0.5 seconds and off for 0.5 seconds.

Not sure how that will effect your solutions.

KEEP will equate to Latch/Unlatch instructions

DIFU is a OSR.

Hope this will help.