Bill Linne

So, in the rung above the COPY operation you describe, I think you should add an EQU instruction that compares the source (ST:10) and destination (ST:2) and if they match, trigger a one-shot to an output instruction to RES ST:10.LEN. That way, on the next scan ofter the copy takes place, the LEN will be rest to zero and you are ready to go. The ONS can be assigned any discreet memory bit address, typically something like B3:1/0. Hope that helps. Bill

It would help if we knew the method of connection in the case of the problem PLC and any others used for comparison. Fully 90% of interface/intercommunication problems are wiring related . . . I'd start by making sure the physical connections are in accordance with specs, done properly, etc. Also, you don't mention if this is a new problem with an old system (that once worked fine) or just what is the situation. Bill

Working strictly from my memory here, I think 6 meters is about twice the recommended maximum. Based on my experience though, it will work just fine. A-B specs tend to be very conservative. I would put a termination resistor at the Panel View. If there is a chance that doing this might affect a critical process, I would not take the chance. Bill

DH+ can be "starred" if the cable lengths are not too long (ten feet comes to mind, but you would want to verify that) which means you can connect more than one device to each port using paralell wiring. Another way to do it is to wire from device #1 to device #2, using the same connector on device #2 wire to device #3, etcetera. The final device in the string shoud have a termination resistor. I have all the A-B references for DH+ if you need specifics (but they are in my office, not here at home). Bill

Hi: At my plant we use Hirschmann products for all fiber applications. The stuff is very durable, and has provisions for dual 24vdc power supplies with auto switch-over in event a power supply fails. Hirschmann makes any number of configurations to suit your needs. The equipment is rail mount, small, and very reliable. Typical installation would be fiber cable from the main control system ethernet switch (which, in my case has fiber and copper ports) to the PLC cabinet, then a fiber x copper module to facilitate connection to the PLC. No special configuration necessary. You won't know the fiber is there once it is up and running. You can hire someone to terminate your fiber connections, or buy the equipment and with a bit of practice, learn to do the terminations yourself. Once we had all our PLC's on ethernet, I changed the MSG instruction rungs to use the ethernet path first, and in event that link results in a .ER bit, switch to the old DH+ MSG as a backup. Very robust system. Having fiber to the PLC cabinets adds great versatility (we used 6-strand fiber, and it takes two strands per circuit). So, I've got spare capacity to add security cameras on their own network segment if I want. You can review Hirschmann stuff here: http://hus.hirschmann.com/English/Industri...cts/index.phtml Regards, Bill

Not to pick nits, Conn, but me thinks you left out the word NOT. Earlier versions will NOT work with it. Is that correct? Sounds like some GREAT new stuff coming down the pipe just in time for my Plant upgrade project. Bill

Okay, Ken. I was just dragging out my activation disks so I'd have serial numbers and all ready for the call to Tech Support. Thanks! Bill

I've a requirement to include Totalizers in a CLX project. I'm new to any serious CLX work, so I poked around and downloaded "MotorRunHours.ACD" which shows what I need. The ladder logic is no problem. Then I see a Function Block Diagram where the totalizer is running in a Routine called Every_1. I can find all sorts of help topics that discuss function blocks but I STILL can't figure out how to get started. I get hung-up at "Insert a Function Block Element from a toolbar". "A. On the FBE Toolbar, click the tab for the desired group of function block menemonics." PROBLEM: Where is the FBE Toolbar?? Is this done in a Ladder FIle?? If not, how do I create a Function Block File?? The only "Type" choice I have when I select "New Routine" is "Ladder Diagram". I think I'm making something simple into something difficult. Any help will be MOST appreciated! Bill

How do I determine which I have, Ken? I'll get whatever activation I need, just need to know how to proceed. Thanks for you help!

I'm fairly new to any serious work in CLX. Done lots of PLC-5 stuff, and now we are expanding the plant and all the new hardware will be CLX. In recent threads discussing PID's, I recall a fairly strong recommendation to NOT use scaled values as PID Instruction inputs. WIth CLX, one of the great things is the versatility of the analog input modules. They do all the alarm setpoints, scaling, all kinds of cool stuff. Seems counterintuitive (to me, anyway) to not take advantage of those features. But if I do, I won't have a "raw" value (0-4095) to input to the PID Instructions. Any help will be appreciated, even a reference to the appropriate manual. Thanks, Bill

After pouring over every other resource I could find, including the Knowledgebase, I just got off the phone with Tech Support. According to Joe, there IS NO WAY to access the raw value. The PID Input IS the Scaled output of the module. I suppose one could scale 0-32767, but that would sure defeat one of the nice features of the CLX A/I modules. Looks like Publication 1756-RM003H-EN-P could use some editing, or at least clarification. Thanks for all the responses. This has been an interesting exercise. Ghettofreeryder nailed it. Bill

Yessir, and because the module can be configured for several different input configurations, I'm not sure what the "raw" maximum signal value is. Referring to the manual, "PV unscaled maximum Enter a maximum PV value (.MAXI) that equals the maximum unscaled value received from the analog input channel for the PV value." In a PLC-5, that value is 4095. What will it be in a CLX module configured for 8 differential inputs? Or are they always 32-bit words, and the module uses all 32 regardless of configuration? Thanks! Bill

Bob: You don't mention room size nor the amount of response (in terms of temperature variation) you get when making changes in your existing system. Also, how often the heat load actually (as a result of machinery starting and stopping) varies and how much that affects AC loading is obviously a factor. I am no guru, but I control a vacuum situation here that is not as exacting as your requirement, but the idea may work for what you are doing. By experimentation, I determined at which point nearing "shut" that closing the valve further made little difference. Then did the same thing on the "open" side. These became my "usable" or "effective" travel limits. So, when something disrupts my vacuum system, that event triggers the valve to travel to the high or low "effective" travel limit, as appropriate. When the vacuum reaches the max of it's deadband, the valve travels to the other end of it's "effective" travel. At that point, the program subtracts 1% from the limit setpoint that the valve just "left" (i.s., if traveling open, it just "left" the shut setpoint). When the process reaches the minimum point of the deadband, the valve travels back to "open" at it's previous point, minus 1%. Then the program subtracts 1% from the other limit setpoint. In fairly short order, the valve finds it's "happy place" and stays there until the next perturbation in the process. This may be too slow and sloppy for your application, but thought I'd send it along just in case. I read everything you write and have learned a great deal - thank you! Bill

Of my OWN money, $75 to $100 sounds fair. Spending "company" money, double that (it becomes a "shop reference" if the company tilts for the cost). I suspect your biggest obstacle would be advertising. Can get pricey, and your "target" audience is rather small in terms of trying to make mass-marketing cost-effective. On the other hand, think of all the systems integration houses and the people therein who would do immoral things to obtain such a reference! Okay, I've probably expended or exceeded my allowance of 'PID High Priest' attention time.

Yessir, you are right about that. Oddly enough, up until early this year, that person was my youngest son! But he left that job to work for an integrator (likes the hands-on stuff better). Have a great evening! Bill

CC & TW: Okay, I knew better than to discuss this without first PRINTING the manual so I could study it! Told ya I don't like e-books. My oversight, sorry. Thanks for keeping me straight! Bill

CC: Actually, with the "popularity" of e-books (which I don't care for), I've gotten out of the habit of looking for the ducumentation ON PAPER. But I do have, and used for hours, one of the applicable manuals, and could not solve the problem. What is missing, IMHO, in the example you cite, is specifics like "A PLC-5 is at DH+ address xx and a CLX processor is at DH+ address yy, and this example shows how to . . .". I actually applaud the use of screen shots. I just happen to think that if an example scenario were created in the manual, and then the instructions (and screen shots/pictures) brought that scenario to reality, it would be MORE useful. The manual, as it is, has value. Is it possible, though, that there are ways to make it MORE valuable? Thanks for your time. Bill

Fair enough. I'm not certain I've ever seen that document, but will look for it tomorrow. I did not examine the entire document (it IS lenghthy!) but even on the pages you cited, I found no examples worded to the effect "if you wish, for example, to send 5 words from here to there . . . ". Personally, the manual would be far more user friendly if such examples were frequently used. The screen shots are GOOD, but could be greatly enhanced by citing an example scenario and walking through it. The info in the screen shots then would have much more meaning. Just my 2¢ worth. Thanks again to all for the help. Bill

Not sure what part of the "procedure" is goofing me up, but I am unable to configure an ABR 7.29 datablock to talk to my new Control Logix box. This is the procedure I'm using: ------------------------------------------------------------- To map a data array to PLC 5 messaging 1. Select Offline from the Processor Status field. 2. Select Map PLC/SLC Messages from the Logic menu. 3. Select the appropriate file number from the File Number column in the spreadsheet. NOTE: This file number corresponds to the same file number you will enter when creating poll records in the ABR Power Tool. PLC 5 messaging does not use a file type designation. For this reason, we strongly suggest using B for bit (binary) arrays, N for integer arrays, and F for float arrays when defining datablocks. This convention ensures the appropriate storage allocation for the defined PLC 5 messages. You should also allocate the maximum size for each PLC 5 message you map to a datablock. This ensures space is available to receive the data. Failure to allocate enough storage space can cause errors and unexpected results. 4. Select a tag from the Tag Name column and click OK. NOTE: If you want to edit the values in the data array for testing purposes, provided you have no controller logic resident to modify these values, you may do so now. To edit data array values 1. Double-click Controller Tags from the tree browser. 2. Click the Monitor Tags tab and select your controller from the Scope drop-down box. 3. Expand the appropriate data array. 4. Double-click the array element’s Value field and enter the desired value. 5. Select Download from the Processor Status box to download the modified messaging operations and defined data array(s) to the target controller. 6. Select Remote Run from the Processor Status box so that your changes take effect. All the information required to process read and write requests to the defined data arrays from the ABR driver are now resident in the controller. ------------------------------------------------------------ Note the final sentence. That is why I selected this method to attempt the link. The part I'm most confused by is the NOTE: section. The File Number selection box will accept NO alfa characters, only numeric. So I figured, okay, N files start at seven in PLC-5's, so I selcected file 7. No joy. Any advice?? Thanks, Bill p.s. I have successfully configured message blocks in the CL processor to communicate with the PLC-5's in my system. The "final frontier" is to get my Scada system to talk to the CL box.

Okay, I'm probably overlooking something obvious, but for the life of me I'm unable to successfully manipulate a contiguous group of C-5 accumulator addresses. Seems simple enough. I want to add the values in the accumulators of C5:0 through C5:29, then divide the result by 30. Everything I try returns an error message that, in typical Rockwell fashion, tells me little more than "You can't do that, stupid!". Any and all help will be greatly appreciated! Bill

Thanks, Ron. I just wanted to be sure I wasn't missing something with a FAL or other file mainipulation instruction. A useful modification to the Counters would be the ability to specify the address of the accumulator, so one could MAKE them contiguous. Thanks again! Bill

I'm instaling my first Control Logix processor, and using RSLogix 5000 software. I need to exchange data between this new processor (DH+ 52) with PLC-5's also on DH+ (address 36, for example). I'm also using ethernet (CLX=10.10.28.52 and the target PLC-5 is 10.10.28.36). I'm unable to configure a MSG instruction in the CLX processor to grab some data from a PLC-5. Has anyone done this successfully? Can you point me to the reference material that includes configuration info for the MSG instruction in the Logix processor? Thanks! Bill

You da Man, Gerry! Why aren't Rockwell's instructions that clear? I spent nearly all day yesterday trying to make that MSG block work, and your brief explanation worked first time. Thank you very much! Bill

I would suggest contacting Rockwell Software. If your 5.25" disks are legit, Rockwell should have no problem swapping you for 3.5" disks.

Because the curve is linear, you should be able to mathematically calculate the output as a function of the input sensing roll diameter. A bit of experimentation would give you the output required to get certain feed rates at various diameters, then calc the curve. A lookup table would also work. Bill