dkennedy2004

MrPLC Member

10

1. 64 bit IEEE double-precision Question

Hi All, I am reading from 4 registers in RSLogix5000 which correspond to a volume reading on a flow computer. The 1st register contains the integer value 16548 = 40A4 Hex The 2nd register contains the integer value -10041 = D8C7 Hex The 3rd register contains the integer value -20972 = AE14 Hex The 4th register contains the integer value 31457 = 7AE1 Hex Now, when I combine the Hex values: 40A4D8C7AE147AE1 and place them in this form http://www.markworld.com/showfloat.html where it says "double-precision IEEE number as 16 hex digits" and hit convert out pops the decimal equivalent 2668.388 which is what is on my flow computer and the exact number I want. Now my problem is how do you get RSLogix5000 to perform this calculation? I cant seem to figure how to do it! Thanks in advance David
2. 64 bit IEEE double-precision Question

Congratulations. Im glad to have been a part of it and im sure it will help many more people in times to come. Regards David
3. 64 bit IEEE double-precision Question

This as been very well resolved for me and I now have a working model. Thanks for the help and detailed explanations David
4. 64 bit IEEE double-precision Question

Brilliant,i got the program reproducing what i want. It was a silly mistake on my part.I owe ye Conn and Bob a few pints of Guinness if ye ever visit ireland! Just one more attachment so could ye make sure that im performing the check adequately as suggested in Conns code and im good to go. Cheers
5. 64 bit IEEE double-precision Question

Hi, Ive managed to get the numbers out using Conns method which is much appreciated but when I run Bobs it seems to give me a Not Convertable output and the real value doesnt come out.Attached is my running code.Ideally i would like to provide this checking that ye are suggesting.Also in my code MCMReadData[142] is the first integer and MCMReadData[143] is second etc etc by the way. Thanks
6. 64 bit IEEE double-precision Question

Thanks very much for that Bob. Opened fine for me. Cheers
7. 64 bit IEEE double-precision Question

Hi Again, Just one more thing.Any chance BobLfoot you could post your code as code done on version 13 RSLogix because I dont have the newer version and im curious as to your method and cant open it.Thats if it isnt too much trouble to do so Cheers David
8. 64 bit IEEE double-precision Question

Will have a look at that link.Cheers. It would be unreal if you could do it in Logix5000, not that im being lazy. Its just that all this bit manipulation I feel could be beyond me.Im just used to creating valve blocks etc in PLC code.Fairly basic David
9. 64 bit IEEE double-precision Question

Hi, Im reading the values over Modbus communications and Im afraid I dont have the option to reconfigure the transmitter to change the output so Im gonna have to invistigate the IEEE 754 standard a lot more. I find all this number manipulation a bit daunting,pardon the pun, so any help would be great in performing the tasks in RSLogix5000. Like for example how do you create a F8 register in RSlogix as suggested? Thanks David
10. DASS7 Server Communication

Hi All, Im fairly new to PLC's and im currently working on a project which is using PCS7 which is as far as i know is siemens answer to a DCS system. My problem is that I want to communicate with it using a DAServer which I have set up in Archestra. The reason being is that I am using a simulation package called PICS which can talk to the DAServer but i cant in turn get the DAServer to talk to PCS7! At the moment we have WinCC communicating over MPI to the PLC. So in Archestra in the CP name section I choose MPI and then next in the VFD parameters section I dont know what to enter.I expected there to be a list in the drop down menu but it is blank and the documentaion states that if blank to make sure the right CP name is chosen! Any help on the reasons for this or tips to the setup would be great. Regards David