I am brand new to Siemens PLC's and need some help!

[semilogical 0]

Today I have been assigned to assist another engineer with project programming on a CPU-315-2DP. We are using a current version of Step 7 software. The biggest problem we currently have is scaling some analog signals. In an older version of the software we have found a SCALE block. I'm going to try to attach an older version scale block and associated programming. I need to know how to setup some indirect addressing (I think). There are some variables that are similar to what follows: #ish #isl #osh #osl The first problem I see is that I cannot find out how to build a new scale block to use when calling the program rungs listed on page 1 and page 2 of the attached document. The new software gies me a scale block that looks like this: Guys/Gals, I could really use some direction here. I'm kind of like the SCUD missiles that were used during Desert Storm - ure [C]ould se [D]irection!!!! Thanks rtc_s7_20070115151438.pdf

[JesperMP 2]

Hi semilogical. The PDF file does not look like that it is from STEP7. Maybe it is MicroWin for S7-200. STEP7 + S7-300/400 has almost nothing in common with MicroWin + S7-200. You cannot share code between the two platforms. Anyway. I dont think you need to use indirect addressing. The "#" sign is used to denote variables that are declared inside a block. You declare variables to be used inside a block in the declaration section that you find above the code window in the editor. However, I think that you should start with using absolute addressing, and then assign symbols to these addresses. This is the easiest approach in the beginning. The red color on the variables you have assigned to each pin is because the symbol is not created, and/or the type is wrong. A tip is to let the mouse pointer linger on the "pins" on the SCALE block. You will then get information about the TYPE that the variables must be. This is the type that you define for the symbol in each case. I hope that this will get you started. If not, continue posting here and we will help you. Edited 16 Jan 2007 by JesperMP

[semilogical 0]

I'm going out to our assembly plant this morning to do a functional test of the wiring in the control system. We have something of a program, I think we might be able to find some answers working online with the processor. I'll explain what we find tonight or in the mornign before we return for the FAT with the customer. Today should be an eye opening experience!! Wish me luck!!

[semilogical 0]

OK guys, here is some questions I'm not having any luck finding answers to. 1. How do I read the data tables? I'm looking at inputs, outputs, and internal values. 2. We have a "hot backup/redundant" or master slave setup. We have two PS and two CPU 315-2DP processors and a PS, two ET200M's, three SM321 (24VDC inputs) three SM322 (24VDC outputs) and one SM335 (4 analog In and 4 analog outs) in that order. the CPU's are mounted with their power supplies above the ET200's and I/O. Where do I go from here? We have no manuals and are not having alot of luck finding anything on the Siemens site. I do have a call in for tech support, but they have been busy today. Remember that I'm not a Siemens guy, all of my professional career has been with AB, GE, and Modicon. Very light on the GE and Modicon. HELP - - - I'm melting!!!

[Crossbow 296]

Siemens technical support website will have plenty of downloads. https://support.automation.siemens.com/WW/l...amp;caller=view

[JesperMP 2]

Hi semilogical. 1. For DBs, you can open the DB offline, and then go to view online (= the button with the glasses). The other way is to create a variable table (a VAT) and then pick the variables you want to view. Again hit the glasses button to view online. For inputs and outputs you can only view them via a variable table. 2. Normally Siemens solution for redundant CPUs is called S7-400H. However there is a "light" software based version for the S7-300 series. I do not remember the exact name. It sounds like this is what you have. You have to purchase additional software. Redundant systems are absolutely non-trivial stuff. You say so, and your questions also confirm that you are an absolute beginner when it comes to S7. On top of this it sounds like you have a short deadline. My advice to you: Hire someone who is proficient with S7 redundant systems, and let him do the job. At the same time you shall take an S7 course. Look over the shoulder of the expert to learn about redundant systems. If you have enough time, you could consider to do it by yourself. But then I again advice you to take an additional course in redundant systems. I wonder how you could have gotten into this situation.

[semilogical 0]

That's exactly what we did - hire a company that was a Siemens Integrator. What we found during the visit was that we had several problems. Wrong hardware, wrong connectors and wrong software. Now we should be talking by Monday. We did find out that the S7-300 is a "Warm Backup" not to be confused with a "Hot Backup" As far as I can tell a Warm backkup will use two RIO Scanners reading and writing to the same I/O. The Hot Backup will have two sets of I/O. I could be wrong but that seemed to be the direction we were heading. The crosstalk between processors has a function block that is loaded with information for the transfer of data, had we of tried to do that on our own we would have been more screwed than we were! Thanks all for the input.