PLC5 to CLX with 1771-ASB

Secpcb

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I have a new project that is replacing the PLC-5/30 CPU with a 1771-ASB and ControlLogix CPU.
This line is all blue-hose comms to 5 racks and the HMI, however a new computer for the HMI required a CLX rack with DHRIO and Ethernet cards - no CPU.
Per a programmer called in for this old line a -L73 CLX can be put in the rack, and the PLC-5 replaced with an ASB module.
I have RSLogix 5 Pro V8, RSLogix5000 Full V20 (which will program a -L73, check first) and have Rockwells free conversion utility.
My fear is that I don't know how to setup the CLX to ASB communications.
Is this something that is easily figured out, or will I require bringing in an experienced programmer for this part?
I haven't told the boss yet I can do this.
 
Is this something that is easily figured out

I think so. The good news is that it sounds like you can go back to the PLC-5 quickly if you run into problems with the conversion.

Does this system have a lot of analog I/O ? Any specialty I/O modules, fast I/O modules, counter I/O modules ? PID loops ? Barcode scanners ? Weigh scales ?

What is the HMI software ? Does it use anything but B, N, and F files in the PLC-5 ? Those are the only datatypes that can be directly "mapped" to a ControlLogix array tag.

A 5-rack system doesn't seem out of reach. I'm a little concerned that you're using a very large controller, but limiting yourself to an obsolete Version of Studio 5000.

There are handful of useful user manuals that describe conversion from PLC/SLC logic to ControlLogix:

https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1756-rm085_-en-p.pdf

And the 1756-DHRIO user manual:

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um514_-en-p.pdf
 
one thing to consider:

just because the pieces of the puzzle will "talk to each other" doesn't necessarily mean that they can talk FAST ENOUGH ...

as long as the system is reasonably slow then you're probably OK ... (example: Bubba mashes the button - and the pump starts up) ...

but ...

if the system is relatively fast then you need to consider the additional "communication bottlenecks" that you're introducing with the new hardware you're adding ...

(example: a sensor counts revolutions of a shaft to tell the processor when the parts are "in position" and ready to clamp ... suppose that the sensor makes the correct count - but by the time the "in position" signal can be received by the PLC, the machinery has overshot the clamping device ... ooops! ...

so ... is it a "fast" system - or a "slow" system that you're working on? ...
 
This has 4 analog input & 8 analog output cards, no fast or PID. THere is a barcode reader on top of each hoist that reads the hoist position. This is controlled in a "Stahl" routine, and that routine is the only one with no PCE errors when I Validate All

The HMI is FIX-32 on WinXP

I just opened the conversion and there are a lot of popups for "Status files do not exist in RSLogix 5000. GSV instructions..."

As for Ver 20, that is the version I have installed and is used on the only other line here with a CLX, I can upgrade to v26 if I had to.

I will download those manual now, thanks.


Ron,
I would consider this a slow system - nothing happens quickly. The total process time for a rack is 3 to 4 hours.
 
let's assume (gosh I hate that word) that your analog input modules are 1771-IFE types ... the "secret handshake" for those is that each module requires a BTW (Block Transfer Write) command to send the module's "configuration" setup >FROM< the PLC's data table locations >TO< the analog module each time the module "starts up" (after a power failure for example) ...

the basic issue is that the RSLogix5000 software doesn't know how to generate the proper configuration data for those older style modules ... so ... before you discard the old PLC-5 project file, go through it and discover what the "magic" code numbers are which are needed by the IFE modules ... in most cases, there will be something like 37 or 39 words of data ... you'll have to track these data locations down by analyzing the settings in the BTW instructions ...

once you've got the "magic" numbers – you'll have to enter these into the ControlLogix processor's data arrays ...

also – the RSLogix5000 software doesn't use BTW instructions – so you'll have to use MSG (Message) instructions instead ... these can be set up to act like BTW instructions ...

if you can post your ENTIRE project file from the PLC-5 (the RSP extension file) then we can offer more detailed help (in case you need it) ...
 
Ron,

I found a lot of PCE's related to messages not set up, I haven't dug into them but that is probably what they are. The cards are the -IFE with BTW & BTR.

Here's a zip of the entire existing RSP with all comments.
 
and here are the 37 words of "magic" data which gets sent to the IFE module referenced above ...

hopefully this will be helpful in getting you started ... I've got to get back to work now - it's amazing how much there is to do once you retire ...

good luck with it ...
.

ife_data.PNG
 
Ron,

Thanks for that heads up.

I am going through all the PCEs now, starting with the easy timers first. One thing I would like some opinions are are the cycle startup of the pumps. Now the pump starts with EQU T4[4].ACC 4 so it starts at the 4th second of a 1.0 base timer. I am thinking if I make it EQU T.ACC 4000 that it might not start - the timer might not be exactly 4000 when the rung is scanned. I am considering LIM 3900 T.ACC 4999

Does anyone have any issues with this?
 
Now the pump starts with EQU T4[4].ACC 4 so it starts at the 4th second of a 1.0 base timer. I am thinking if I make it EQU T.ACC 4000 that it might not start - the timer might not be exactly 4000 when the rung is scanned. I am considering LIM 3900 T.ACC 4999

Does anyone have any issues with this?
Good move. That is exactly what I've had to do in the past.

One note with all of your analog cards: Each ASB module can only handle one block transfer at a time, so you'll want to manage your MSG instructions so that they fire one at a time. Now if your modules are spread out over multiple racks, you can execute separate rack MSGs simultaneously. Search the forum for "message manager" to bring up other forum posts on the subject as well as the link to an A-B document on Logix5000 messages.

Edit: Here's the link to the doc.
 
Last edited:
RonJohn,

11 analog cards are in one rack, with 4 in another rack - so hopefully they are controlled that way already. But, I will go through to make sure.
 
Another little question -

There are 4 status bits (S:7/1 to S:7/4) that report the fault status of the 4 racks that are checked in the program.


How would a CLX show those faults?

Will it have to read them from the -ASB first?
 
The tags that get created for each 1771-ASB adapter under the 1756-DHRIO's RIO scanner channel have a Rack Status word, and Bit 0 is "Fault".

[AdapterName]:I.RackStatus.0


The 1756-DHRIO will generally handle 16 block transfer modules without having to get into complicated buffer expansion logic. The QTS-built 1756-RIO and the standalone EIP/RIO scanner module handle very large RIO analog systems better.
 
I have been working on the conversion.

One thing that surprised me was that about 80% of the comments weren't copied over. Going through the entire program rung by rung and copying and pasting from the RSLogix 5 program for each integer, real, BT, bit and IO point.

At least al the rung comments made it.
 
I have the conversion done, except messaging, in ver 20.04.

I downloaded and installed ver 26.01, with some help from Rockwell because it kept crashing on Logix Motion Designer version problems.

I made a copy to update to ver 26, but when it opens it opens in v20. That is to be expected.

However when I go to Controller Properties, Change Controller, and select 26 from the drop down menu, when I hit OK Studio5000 goes busy for about 2 minutes, then when it responds it still shows v20.11.

I have tried to open a new project and see if I can then open it in the new version, but that doesn't work either.

What is the proper way of changing the version on a CPU? 1756-L73, which I haven't tried to connect and download to yet - just select the CPU.
 

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