Gnomes

Hello, I have some more questions that perhaps someone may be able to help me out with. I'm still pretty new at working with these. We have an old plc which was programmed using, i think, logicmaster 90 micro software. We want to edit the program that is installed on the plc to see if that helps in getting the machine it's on working properly. We recently purchased a new plc and we have machine edition software that I've been playing around with a little bit. I was wondering if it's possible to be able to use machine edition to edit the program made with logicmaster and then download it into the old plc using the machine edition software. Thanks for any help!

Thanks Russ, It took me a little searching to find the "status", but I came across it eventually!

Hello, I've just got a quick question about program memory. How can I find out how large my program is, how much of the program memory will I use up. I'm wondering if a program that is on a Versamax we have will fit onto a versamax micro or nano. Thanks for any help!

I have an rs-232 to rs-485 adapter cable and I'm running into some problems when I'm trying to go online with the plc using the 485 port. It appears that the baud, parity, and so forth seem to match up but I'm wondering if there are some other settings I need to set in order for me to go online and use this port for programming. Thanks for any help!

Hi, I've been trying to connect with a VersaMax controller using the 485 port. I would like to try and use this port for programming and the rs-232 port for serial communications. I currently have a 485 box connected inbetween my computer and the plc. For some reason I haven't been able to connect with the plc yet, do I need more then the 4 receive and transmit lines the black box has? Running into some trouble just seeing if anybody out there can help out at all! I've been trying to use the same port for programming and sending serial data but it doesn't always seem to work consistently for me and it doesn't always receive data, the status byte shows an error of 1037(decimal) which according to the book means "Receive timeout awaiting serial reception of data" and I haven't figured out what to do about this error. Thanks!

Hello, I'm having some trouble trying to get my counter to reset all the time. In the following pictures part of my code is shown. The problem I'm running into is getting my counter LDCNT to reset. It will reset after the call function LDIS but it will not reset after the call LEADRE and I'm not sure why it won't reset. Both call functions seem to work correctly but after one of them the reset will work and after the other the counter doesn't reset. Any help on this problem would be great and if for some reason some more information is needed just let me know! Thanks!

OK, I think I'm starting to understand what you're trying to say and how this programming operates. So during my testing of this program when I was able to get the counter to reset only after the function GT INT was true was because the coil LCTRRES wasn't turned on in the earlier rung thus not having a chance to get turned off on rung 21 (if it's logic was false) before the program swept back around to the counter. So if I get this right, if I would swap rungs 15 and 16 with 20 and 21, the counter would now only reset after the call to LEADRE and not after the call to LDIS? Also if I removed rung 21 and only had the one coil on rung 16 to reset my counter it would probably work there as well? (I will edit my program to try this for fun) Thanks for your help Steve, I've been doing most of the learning by myself with little previous experience and some answers to questions such as these are appreciated!

Thanks for your help Steve. I switched some things around and tried what you suggested and so far now my counters always reset when I wish them too! Trying to correlate your explanation with my code I'm still not quite sure what the problem was. I thought that if my ldcnt was in the range it would fire off the reset and if it was greater then 17, it would fire off the reset then. My code would reset the counter after LDIS was called so I was getting a little confused. In your response you said that the lctrres bit is turned on at rung 16 and then turned off at rung 21, how is it turned off at rung 21? Thanks again.

LEADRE call function

LDIS call function

Thanks for the help Steve. I will keep that information in mind.

I've got a quick question that I'm wondering about here as I'm trying to figure out some code that might work with what I'm trying to do. How short of an input signal is allowed for the plc to recognize an input and close the correct contacts in my logic? I'm using a VersaMax PLC with cpu001. Thanks for any help!

Hi again, I'm not sure if it's possible to do or not with the setup I'm using. Using Serial I/O protocol is it possible for me to send an 8-bit byte using a write bytes command or am I only able to send ascii characters with this protocol. I want to use it as sort of a status byte which will tell me if whatever I have attached to my inputs are being used or not. Thanks for any help!

Thanks for your help Steve and Russ. I moved the one shot coil and that seemed to solve the problem I was having now it's time to try and see if I can figure out some other troubles I'm having!

Hello, I've been experimenting a little with using subroutines and call functions. I'm running into a problem and I don't know why it doesn't work. Below is a picture of my main code. In the first two subroutines (Hello, Clear) are just some block move instructions that set up a data block for the commreq. The last call command (dummy) has some move instructions along with the commreq. All of these commreq's are for a write bytes command. Hello prints hello to my hyperterm window while clear is a new page command (Clears my window) and dummy prints dummy. What I'm running into is after downloading my program to the plc I flip input one and hello appears on my screen. I set input two my screen clears, then I switch on input three and dummy appears on my screen. So everything seems to be working all right. So I try it again and there is hello and clear page but I get no "dummy" appearing. It looks like when I have the commreq in my call function it only seems to work on the first time after downloading the program whereas when the commreq isn't in my call function it appears to work every time. What do I have to do to be able to keep my commreq in my call function for it to work each time? Thanks for any help!

Here's a picture of the Dummy subroutine. I am using a one shot for my commreq and from my knowlege I thought this would work but for some reason it only wants to work once on the intial power up of the plc and then no more. So it's also a good idea to use a one shot when using a call funtion as well?

I'm having a little luck now with turning on an output. I send the plc character 1 using hyperterm and my output turns on, however when I try sending it a zero nothing happens the output is still turned on. Unable to turn the output off yet. Still manually setting inputs to read what I send the plc. No luck yet with trying to figure out a way around this, if possible!

Hi again, I've been playing around with using the serial ports with some varied success. Now I'm wondering how to accomplish my next task/goal. I would like to be able to turn an output on or off depending on what I send to the serial port with my VersaMax PLC. Has anyone ever done this or have an idea of what to try, right now I'm a little stumped on what to do. Thanks for any help!

What I've currently done just to start getting a little familiar with this is, using the 232 port for programming and the 485 port for communicating with a windows hyperterminal session. The 485 port is configured for serial i/o (from a suggestion given earlier to me). We purchased a starter kit and in that kit an input simulator was included which is sort of pretty handy so that's what I'm using to turn my inputs on and off. - I first turn on an input and it flushes the input buffer. - Next I type a message in the hyperterm window and send it to the plc - I then use a read input buffer and store the message in memory - Then I use a write byte command and write the portion of memory where it is stored. This seems to work all right to me. I just want to figure out if there is a way for me to do this, as well as having an output turn on, without having to manually switch inputs on and off. Any ideas? Thanks again!

I'm not sure exactly on how to go about turning the right output on. If I'm thinking about this correctly when something is sent to the PLC through the serial port it goes into an input buffer first and then you have to do a read bytes (or string) comreq to get that information. So am I right in thinking then that there isn't a way to have an output turn on simply by sending something (some string of characters or something) to the plc through the serial port? Thanks for any help.

Hi, I'm trying to experiment with the RS-232 port and some serial communications. I'm using a versamax plc with a cpu001 and machine edition software. What I would like to be able to do is when a certain input is set, a certain output response is sent out through the rs232 serial port. I'm not sure what steps are needed to accomplish this. I've messed around with trying to use COMREQ commands, I've tried to set up a few data blocks (One for serial I/O, Initialize port, write bytes) which seem to be a little tricky for me to create and keep track of (not to overwrite any or something like that). What I've tried to do to see if my program works is after the program is downloaded to the PLC and the outputs are enabled, I go offline from the PLC and then open up a hyperterminal window, which uses the same cable and port that was just used to program the PLC, to see if my message appears when the input is turned on. So far I haven't been able to get any type of response. I was wondering if anyone has ideas or suggestions for me. Thanks for your help.

That PLC was shipped to me from an outstate plant with the box and so when we changed the program on the plc and sent it back to the plant the box went with it. So that leaves me right back at the beginning!

It's been awhile but I've finally have some more time to come back to this project. I've still been trying to use the same port to accomplish both tasks (write a program to it, then use it to send an output in response to an input being sent) only because we currently do not have any converter or cable to use the rs485 port. I went through my program again and I was able to pick out one error when setting up the data block for the serial i/o comm_req. Is there a particular order for using these comm_reqs? Right now the program follows the format of setting up data block then using the comm_req starting with the serial i/0 protocol first followed by initialize port and then finally write bytes. I've also come across this write port control command and I'm not sure what this means and if it's something I should be trying to use or not. Someone mentioned something about checking data offsets. I'm having some difficulty with doing this. I can't seem to find out what offsets, if any, I need to check or where to look. The only one I think I see is for the status pointer offset but other then that I'm not sure what else. And finally after I try to run my program two of my outputs turn on supposedly indicating that my comm_reqs didn't work. When I get back connected online with the plc I look in the register memory table and the values where the status word is supposedly going I get several different numbers. In the spot for the serial i/0 protocol I get a 1 (does that mean that it worked correctly?). Then for the initialize part I get a 524 and the write bytes spot a 0, which I'm not sure what errors these may be referring to. Anyways thanks for any help and in the meantime I will continue to beat my head against the desk!!

I was finally able to get it to work. The cabling we used ran through a 485 box, I ended playing around with some other port settings. Adjusted the transmit and receive buffers and after playing around with them the firmware upgrade worked and then I was able to use the machine edition software to program the plc. Thanks for trying to help me out and I'll probably be posting again for some help!

I'm using the one under the little flip lid, i didn't even know there is another one hiding.