Allen Bradley DTAM

[bskup]

Hello,
I have a machine that had an SLC 5/02 with Link Coupler, DTAM, etc. and the processor and power supply failed, losing the program. Tried going to the OEM, but the 5/02 is obsolete, so an easy upgrade is a 5/03, right? Well, i got the program loaded, and the DTAM sort of works.
Previously, the DTAM would display a message like "Enter Timer #" and it would allow the operator to select one of 18 or so different timer functions; pressing timer 1 would display "cooling delay 2600" which was 26 seconds preset on T4:2, and you could change the value there, pressing next would get timer 2, etc.
My question is if I wanted to use a simple HMI to replace the outdated 5/02 and DTAM hardware, what destination can I tell the HMI to send the new value to?
Would it be T4:2 Preset?
Or an Integer?
I ask because the ladder logic shows a lot of N7:230's, B3:6's, and only a couple of MSG instructions. I've done a bit of programming, but nothing involving the DTAM, which is decades old. Shame it stopped working because those things were rock solid.
thanks in advance

 

[the_msp]

Welcome, I've been there, albeit 2008; DTAM on 5/02 Upgraded to 300 Micro on 5/03.

Don't write or read directly from PRE, ACC, etc. The N7 files are integer files that should be used for that purpose.

 

[bskup]

Thanks!!
So to clarify, I shouldn't have to change the ladder logic, just my hmi program tags to go to the integer files , NOT the timers, even though the messaging was handled through the 485cif or whatever?
I'd love for someone to show me how to take one timer assignment and upgrade it to another(not allen bradley hmi). This legacy/obsolete hardware is frustrating. Hours with A/B tech-connect's brilliant engineers, but most were born after the DTAM obsolescence and never heard of that.

 

[joseph_e2]

If you want to avoid changing the PLC code, your replacement HMI will need to read/write the same registers as the DTAM. If the DTAM is writing directly to the timer presets and you want to write to integer registers instead, then you'll have to edit the PLC code.

 

[the_msp]

I changed my program to make it easier for me.

I haven't seen your program.

You will need a licensed copy of RsLogix 500 to work with a 5/03.

HMI wise, I would grab a Weintek, I know they aren't as popular in the States due to their country of origin. So perhaps a RedLion etc, something on short leadtime, with the correct drivers.

I still have a 2006 laptop with proper serial port and all the software. If I was closer I would offer to help directly.

 

[plvlce]

As joseph_e2 noted, you can avoid touching the PLC code if (and probably only if) you can identify exactly where the DTAM was writing to and point the HMI to the same registers. If the DTAM directly addressed T4:2.PRE, the HMI will have to as well, but if the DTAM actually wrote the value to (eg) N7:230 and then the PLC logic moved that value into T4:2.PRE, then the HMI will need to write to N7:230 or else whatever you put directly into the timer may be overwritten by the stale data from the integer file.

Of course, if you can modify the logic then you can set it up whatever way you want.

For HMIs with SLCs using DH-485, I've been putting in AutomationDirect C-more HMIs (mostly upgrading from obsolete Panelview 550).

 

[joseph_e2]

My go-to for RS232/DH485 was the Red Lion G3 or CRx series, but their lead time is way beyond reasonable. I'd look at the C-More for this as well.

 

[Operaghost]

The DTAM and other HMI devices can write directly to the timer preset or to an integer file. Either method is allowed.

If the HMI is writing directly to the timer, then you wouldn't see any logic showing that this is happening. That is one of the downsides. The data just appears in the PLC without any idea where it came from. With this method it is important to have comments in the program that identifies where that data is coming from. Also, you are relying solely on the HMI to validate that the data is valid. Not too big, not too small.

If the HMI is instead writing to an integer file, then that allows the programmer to have the PLC test the number and see if it is "acceptable". We can write logic to make sure the number isn't too small or too large. If we determine it is acceptable then we include logic to move that number into the timer preset. This is usually the more preferable way to affect the preset. With this method, we will be able to find that logic easily enough. You can do that one of a couple ways

Use the Cross Reference Report

1. Open the logic and locate one of the timers.
2. Right-click on the timer address (ie T4:0) and select Cross Reference to open the Cross Reference Report.
3. The report contains a cross reference for every address but it will have jumped to that specific timer. In the report look for an item addressing the timer preset. Usually just a line or two down from the timer itself. Most likely an MOV type instruction. It will show you the File and Rung number where that logic is located. You can double-click on that line to jump to that logic. The Source of the MOV is likely where the HMI will need to write.

Use the Embedded Cross-Reference

1. Right-click on an empty portion of the ladder logic window and select Properties
2. Click the Address Display tab along the top
3. At the bottom select Display Cross Reference for Output on Rung and click OK
4. In the logic underneath every output instruction (including timers) you will see a yellow field identifying where any of the output elements are being used. Look for anything addressing the PRE and you will see the File and Rung number where it can be found. Click on that location and it will jump to that file/rung.

Be aware that this method would persist even after you close this file. The next file you open would show you this embedded cross reference detail. But, for me at least, that's a good thing.

So again, it is acceptable to write directly to the timers or to integers. You just need to identify which method they are using.

OG

 

[joseph_e2]

The in-line x-ref is probably my favorite RSLogix 5/500 feature that didn't make it into 5000.