Steve Bailey

Your garden variety SSR with 24 VDC input and 5VDC output will do it but they are limited to about 5 kHz frequency. The Calex 8501 or 8502 will do what you want and it can handle up to 20 kHz frequency. http://www.calex.com/pdf/8501_02.pdf

There are a couple of possibilities, but both of them are based on the need for this to be a unit with a CPU module and not one of the CPU in the backplane units. There is a CPU module that has two serial ports. That's IC693CPU363. You could replace the existing CPU module with a CPU363 and now you have two additional serial ports available. There is also a serial communications module IC693CMM311. It installs in a spare slot in the same rack as the CPU module.

Try Qualitrol. They're in North Carolina, not Louisiana, but they are the source for obsolete GE parts and service. http://www.qualitrol.com/

The program you posted has sixty instances of the TS instruction. Which is the one with the problem? Furthermore, the presets for most of the timers are either registers R00271, R00258, or R00259. R00258 gets loaded with a value of 15 on rung 3. R00259 gets loaded with a value of 30 on rung 4. R00271 gets loaded witrh a value of 5 on rung 5. The only TS instruction that does not use one of theses three registers for a preset is the one on rung 1047 which uses a constant of 2. The bottom line is that I could not find any TS instruction that has a preset of 60 seconds.

The first thing I would do is to make sure the register assigned to the timer function isn't being used anywhere else in the program. That's the address at the ACCRG location in the function. Be aware that Rxxxx addresses in a Series Six share the same memory space as AI and AO bits, so it's possible that ladder elements in the program could be altering the register value. Be sure to perform an implicit search rather than an explicit search when looking for other usage. Explicit search will locate all usage of the Rxxxx address. Implicit search will locate 'hidden' usage such as the second address of a 32-bit instruction. If possible, post a copy of the program file and I'll look at it for you. I have a Series Six that I can download it to and see if I get the same results.

Try these folks. http://www.qualitrol.com/html/techsupport_gefanuc_programmingtools.asp?Product_Line=Series%20Six

Intermittent I/O parity errors like that can sometimes be caused by a bad backplane connection. Try removing and reseating the modules. Be sure to use the tool so as to get the maximum seating force.

All I could find was this from the Logicmaster Six manual: CPU error flags are stored in Scratch Pad memory. The CPU uses these flags to record faults encountered during normal operation, or during self-checks. This display is always controlled by the CPU. If any of the error flags is set, a message appears on the line below the error flags line.

If the LED on the module does not light up when the program turns the output address on it could be that the PLC has lost its hardware configuration file or the file you have downloaded to it assigns the wrong address to the module.

Contact me via the site and I'll give you my email address. Then you can send me the Logicmaster files and I'll make a text file of the program for you. If you need on-site service I'm available for that as well, but I'm located on the East coast. I have an old DOS computer with a parallel interface card for communicating with the Series Six.

I'm not aware of any "backdoor" password for a 90-30. If the technician doesn't know the password, he'll have to guess it.

Yes it is possible. As long as your technician has the programming software and the program in the other machine is not password protected, then he will be able to upload from the other PLC and download to the dead one. There's no guarantee the program in the other machine will be exactly what you need for the the one without a program, but if it is a similar machine from the same manufacturer, it will be start. I have worked for more than one machinery builder and I can tell you from personal experience that two machines don't always get shipped with identical prgrams, especially when the machines go to different customers or if there is a long time between when the two machines are built.

I'm sorry, but I don't know Citect very well so I can't offer details about how to set up a specific instance of their communications driver. All I can say is that you should be able to copy the setup you already have for a 90-30 or 90-70. The name of the GE communications protocol is "SNP" or SNP-X" for serial communications and probably "SRTP" for ethernet.

The same driver that works for the 90-30 and 90-70 will work with the Rx3i. The only issue might be in the way the Rx3i program is written. The Series 90 PLCs were limited to numeric addresses and an older communications driver may have the same limitations. The Rx3i supports symbolic addressing and doesn't require a numeric address, although one can be applied. For example, in a 90-30 you couold have an integer variable called "Widget" with an address of %R00101. That same variable in an Rx3i could simply be named "Widget" without assigning the %R00101 address. If the programmer of the Rx3i didn't use numeric addressing you'll need to make some modifications.

Tell your teacher he's asking the wrong questions. All of the specifications published by the makers of PLCs are nothing more than tools for you to use to determine whether or not a particular model is capable of doing the task you need it to do. If there were a single set of specifications that defined the "best" PLC, then all manufacturers would offer a model that met those specifications. If the CPU that can handle 100 I/O points costs $100 and the CPU that can handle 200 I/O points costs $1000 and the job you need a PLC for requires 75 I/O points, which is better for the task at hand? On the other hand, if your facility already has 50 of the $1000 model and your entire maintenance staff is familiar with it, does it make sense to use the less expensive model? But wait, suppose the $1000 unit of which you already have 50 in use has been declared obsolete by the manufacturer?

Current signals typically use a 4 - 20 milliamp range, so any value below 4 milliamps can be interpreted as a broken wire or a failed sensor. Within the limits of the sensor, the signal is not subject to line losses as a voltage signal would be. The advantage to a voltage signal is that it is easier for a technician to measure it with a meter.

I'm pretty sure you'll have to do it with a script. I don't think there is a dedicated "Page Change" variable.

I was in a similar situation a few years ago. There is a free version of Proworx32 available for download, but it will only let you see (or print) the first 25 networks. But, once you've printed the first 25 networks, delete them and you can view the next 25.

There is no "trial version" of the programming software. The trial is simply the four day period during which the software will be fully functional without having to be licensed. After the four day trial period, if it can't locate a license, the software will not let you go online with the PLC, nor will it let you save any changes you might make while offline. Any distributor can choose to give you a copy of the installation CD. It all depends on the relationship you have with them. If you buy stuff from them on a regular basis, they will be more likely to do you a favor. If the only time they ever hear from you is to complain about how the stuff they sell is s**t compared to their competitor's products, they'll be less likely to help.

I doubt if your problem is with the PLC hardware. All brands of PLC have pretty reliable built-in error detection. If they detect something amiss, they generally shut themselves down completely, turning all of their outputs off. The software you're looking for is probably Versa Pro, although that's no longer being sold. The current software is called Proficy Machine Edition. If you can get a copy of the Versa Pro installation CD, you can install it and the software will be fully functional for a four day evaluation period. After that you won't be able to save any modifications you make. You can uninstall and reinstall to restart the four day clock. The real challenge is getting a copy of the CD. It sounds like your distributor is unwilling to give you one. My experience with intermittent problems is that they are a response to intermittent anomalies in the operation. By that I mean that the program successfully accounts for the way the operator runs the macine most of the time, but every now and then something happens slightly out of sequence. It could be the operator pushes the buttons in a slightly different order. It could be that a photocell is blocked a little longer than usual due to a box being slightly out of position on a conveyor. For whatever reason, the difference is enough to cause problems. It's possible that your problem with timers is in the way the original programmer wrote the program. If he was unfamiliar with the 90-30 he could have made a common error. GE timers work a lot like AB timers, but the 90-30 memory map doesn't include a predefined timer area like AB's T4 memory. Instead, each timer uses three words of %R memory. %R memory in a 90-30 is similar to N7 memory in AB. If the programmer didn't keep track of his memory usage, he could have assigned the one or more %R addresses to two different timers. You might get away with the overlap if the two timers don't have to be timing at the same time, but if both are active simultaneously you'll get unexpected results. Its something to check for once you can get the software and take a look at the program.

Market leadership depends on a lot more than simply having a unique feature. Granted, it's a nice feature and it gives them bragging rights, but I haven't heard too many of my customers bemoaning its lack on the HMI panels they're using. Furthermore, anyone who thinks it would be a good idea to take advantage of that feature to implement two-hand control doesn't belong in the industry. It's actually two-finger control, and on a small screen those two fingers could easily be on the same hand.

You should compare the hardware configuration file you pulled from the PLC with the actual modules in place. Any discrepancies between what is actually in place and what the configuration file is telling the PLC CPU to expect, could be the source of the fault you reported. Be sure to look for the CPU rack and two additional I/O racks in the configuration file.

If I remember correctly, VersaPro has three options regarding firmware checking. They are "prevent download", "allow download, but warn", and "allow download". It may be that your previous cersion of VP was set up to allow downloads to older PLC firmware versions without warning you about mismatch issues, and that's why you haven't seen that warning before. The 8.21 or newer firmware version "limitation" has been in place for a long time. I put the word "limitation" in quotes because as far as I know it isn't a hard restriction. It's just that there are known compatibility issues between VP and older firmware levels. If your program doesn't include any of the problem areas, you could be OK downloading from VP 2.04 to your CPU. Consider this: There are some CPU models that were discontinued before they ever got to firmware version 8.21. If you look in the Versa Pro help files for the firmware compatibility table, you will find CPU models with firmware versions earlier than 8.21 that are listed as compatible. That's because there is no version 8.21 firmware for those modules. The version listed is the highest available firmware version for that particular CPU before it got taken out of production. I was once told that the most significant issue between VP and earlier firmware versions was that certain actions taken while online with VP could cause the CPU to stop running its program. An example might be something as simple as opening the PLC fault table. If the process controlled by the PLC can withstand the PLC stopping for no apparent reason, then you may be able to use VP 2.04 without having to get a new firmware chip. This is truly a "caveat emptor" situation. I can't make a judgement as to whether you should risk downloading from VP 2.04 to the firmware level in place. All I can do is tell you that you can. The other reason I bring this up is because if you have opened the project folder under VP 2.04, you may no longer be able to open it with an older VP version. That's because unless you specified "close project without saving", when you closed the project, it was automatically saved as a version 2.04 project, which can't be opened by earlier VP versions.

That's what I had in mind when I said the Click is "underpowered" for this application. From the description, I can envision this project to need some analog signals before it's done, specifically, vacuum level, maybe temperature, maybe analog speed control for one or more of the motors. Since the OP isn't really sure about what his needs will be, I think starting with a platform that gives him more room to grow is a good idea. Incidentally, I'm not sure how Automation Direct prices compare with the competition in Great Britain, or exactly how Koyo products are marketed there.

20 I/O is way too low a count for the syatem you've described. Your list of items to be controlled is a minimum of 19 outputs. Do either of those two motors that drive the mixer need to rotate in both directions? You need two outputs for each motor that can run in two directions. About those ten pneumatic cylinders. Depending on the style of solenoid valves you choose to control the air flow to the cylinders, you could need two outputs per cylinder. You haven't mentioned anything about inputs. Are you going to install switches to indicate the position of any of the components? How about pushbuttons to start and stop things? Are you going to use an HMI panel? My first impression is that the Click is a bit underpowered for this application. If you're going to use something from Automation Direct, I would start with a DL-06.