BenJones

Hello All, This is my first post in the Siemens part of this web forum. I have used a Mitsu FX PLC before but new with the Siemens S7-300. I am using a CPU314C-2PN-DP which has 4 integrated/onboard high speed inputs (channels 0,1,2&3). I am using these to read in a frequency from a water flow meter where 2-20 L/min corresponds to 20-225 hz. I'm struggling a little with getting them to work. I have found the S7-300 CPU 31xC: Technological functions manual and also an example program. I've also found the FB here : https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo〈=en&objid=18475558&caller=view I have also found the sample example here : https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&objid=9837059&nodeid0=33519671&load=content&subtype=133100&switchLang;9837059;2.x=34&switchLang;9837059;2.y=4〈=en&siteid=cseus&aktprim=0&objaction=csview&extranet=standard&viewreg=WW I have attached the example to this post that I'm particularly interested in. I am using TIA portal V11 and V12. I have tried to migrate it from V5.4 to TIA V11 or V12 but I get an error message. Could someone please try and migrate it for me? Also, if anyone has used this FB before could they help explain how I wire the flow meter as I'm a little confused. It mentions in the manual but I'm still not sure. The direction is only one way and I'm just reading in a sqaure wave (0-24VDC) Many thanks in advance for any help, Ben Cnt_en.zip

Ok thanks guys. I don't think there is any easier way to do it. It's ok though, I've finished off the program to read in the number now (the long way!). If you do come accross the same problem in the future then the code I attached will work. Thanks for your comments and help, Ben ps. Is there any way to mark this post as 'completed/finished' or shall I just leave it ?

Hi ! It seems very strange that the manufacturer (Areva) presents the data in this format ! I have done some programming (took me ages) to try and read the number by splitting the data into the upper 8 bits and the lower 24 bits, so I now have the signed exponent and the mantissa, but I don't know how to put this as one number and display it on the HMI (E1101). Been trying to read this number and put it on the HMI for about three weeks now. Crazy ! I've attached the Areva kWh meter manual as well as the programming which I have done (in IEC Developer). The Data type is under 'Data Types' in the manual on page 27. The modbus addresses which I'd like to display the values of, are 36-41 on page 16. (I can read from the addresses no problem). There surely is an easy way to do this because why would Aveva make there data so hard for a plc to read from their kWh meter ? Any help is much appreciated. Thanks, Ben AREVA M231 MANUAL.pdf MODBUS_READ_CURRENT_backup_file_change _extension_to_pcd.pdf

Hi, thank you for your continued help. I'm still having problems. I think the problem is as follows : Please look at the 2 attachments. The PLC reads a floating point number as : Mantissa : 23 bits (b0-b22) Exponent : 8 bits (b23-b30) sign : 1 bit (b31) The modbus data type is read by the PLC from the kWh meter as follows : Mantissa : 24 bits (b0-b23) Exponent including sign : 8 bits (b24-b31) Does this mean that when the plc tries to interpret this as a floating point number it will not do it correctly because the bit order is different ?

Hi Kaare, I can get the number shown in the OP no problem with 'FLOAT WITH EXP' but I don't think it's the correct number. I don't think it has converted it to decimal, I think it has stayed in binary with exponent. I may be wrong just a bit confused. Looking at the example from the manual it says that 123456 x 10-3 is stored as hex FD01 E240. When I convert FD01 E240 in the PLC I get -1.0790 to the power of 37 and I think this is base 2 binary and not base 10 decimal (surely the number I should get is 123456 with exponent -3. I downloaded an excel spreadsheet tool which converts to precision floating point number. I get the same number as the spreadsheet tool -1.0790 to the power of 37, when inserting FD01 E240 but is this base 2 ? If so then I think I need to convert this (somehow) to decimal !? ieeefloats.xls

Thank you for your help ! Kaare your method did work. I now have the hexadecimal number FD01 E240 in binary floating point format ( -1.079032... x 2 ^ 37). I think I need to now convert this base 2 number (binary) into base 10 number (decimal). Is there an easy way to do this ? I've looked through the programming manual and searched through all the function blocks but can't see an easy way to do this. I used the DEBCD scientific notation function but this didn't put the number into decimal format it just put -1079 into D and 34 into D+1 ie representing the mantissa and exponent in the same base (-1079 x 2^34) Thanks again, Ben

I'm having difficulty presenting a 32 bit number with exponent on my SCADA screen (E1101). I am reading the 32 bit number into 2 x D registers after reading the data from a kwh meter. I can read the data from the kwh meter device (via Modbus RTU). I am using IEC Developer. The parameter I wish to read is 'current' (Iph1). The number is represented as 32 bit unsigned number (of Type T5) please see attachement. The 24 least significant bits are a binary unsigned value and the 8 most significant bits are the decade exponent. First question : Is there an easy way to read/view this 32 bit number with an FX3u and E1101 (maybe using float with exponent or 32 bit unsigned or something) ? Second question : Do I have to use some more complicated method to read the data ? If so, I was thinking I must have to separate the most significant byte (which is the exponent) from the 32 bit number. Then I'd need to use a roll left function to roll by 8 bits and then shift function to shift by 24 bits right. Bloody complicated ! This would represent the binary number as 00000000 XXXXXXXX XXXXXXXX XXXXXXXX where X is the binary value. I could then multiply the binary number and the exponent. There must surely be an easy way to do this or do I have to use the more convoluted mathematical method ? any help is appreciated. Thanks, Ben data type.bmp

Hello All, Has anyone had the problem where data log files have stopped being attached to an email when using the E1101 HMI (using an SMTP server). I've set up time channels to send me a daily email with a data log attached. For the first month the emails worked correctly and attached the data log. The data log getting bigger on a daily basis up to 1MB before its full an then it just over rights a days worth of data and stays the same size. This has now stopped working and I don't know why. I now get an email on a daily basis but it stops attaching the log file after a day or two. The data log gets to about 20kB after a day or two and I still get the email but it doesn't have the data log attached ! Does anyone have any idea why this might happen ? It's really puzzling me. I've checked that the SMTP server is not stopping large file sizes (which it's not). I can set time channel to send me three or four emails before the log file stops getting attached so I figured it must be something to do with the file size. I've set up the data logging to save 20160 samples (7 days at a sample rate of 1 sample every 30 seconds). The max limit I've also set to 20160. Has anyone else had this problem ? Many thanks for any ideas. Ben

If anyone gets the FILESIZE error I know how to fix it. You have to compress the bitmaps which the program uses. If any of the bitmaps within the project are ticked on the 'stretch' function (within static object properties) this needs to be un-ticked as re-sizing the bitmaps takes a lot of memory. If you look at the 'symbols folder it shows you the bitmap sizes.

Hello,m has anyone got any ideas of how to rectify the FILESIZE problem. I can no longer upload my file to the E1101 HMI. The file itself is not too large in size. I don't know what the problem is so any help would be useful. Thanks, Ben

Hello, I've just had these errors as well and consequently can't upload a program. I tried to change the alarm size to 5kb and 10kb but to no avail. (see attached) Do you think I may have to add some external memory ? After uploading from Edesigner it now says my file is 3500kB. Is this too big ? Many thanks, Ben

Hello, A company (Cryomech) supply us with a cryocooler and this has a controller made by a company (Sycon). I wish to connect to the controller to my PLC (Fx3u) using a serial card (RS485_ADP). I'm also using IEC developer. The protocol in question (SMDP) is not well known and they haven't got around to re-programming it with an industrial standard protocol like modbus or profibus. This of course makes things more tricky to program and I can assure you that I'm NOT the best programmer in the world ! The Mitsubishi guy say I'll have to program my own driver using the RS2 non-protocol. I have got no idea how to do this. I've got RS2 function block to work before (with Beijers modbus solution pack) using Modbus RTU but the SMDP uses ASCII. I don't know to program ASCII or even know if this is possible with the Mitsubishi stuff. Any pointers in the right direction would be useful. I've attached the protocol reference manual. Thanks, Ben data_dictionary.pdf Sycon Multi Drop Protocol II.pdf

Ok, sure, we'll probably be sticking with the FX then I think. Seems to do what is says on the tin and should be ok for the next project too.

Ok, thanks Crossbow ! . I shall think further about the amount of information I need to transfer