How to read value from weighing scale to S7-200

Hello,

perfect to me, looks ok isn't it? Maybe one disadvantage that you don't see hex representation of each char/byte, then you'll be also see all chars/bytes in received message, now you see only characters from ASCII table which have visible interpretation as chars. Some control characters can be also beep sound f.ex. Try sum all bytes from your documentation how received message looks like. Your control chars are CR and LF and also these must be sum, simply each byte from message format. Try find some other application (hope I remember good Hercules??? application) and use it, there you can see also hex format where you can decode also other chars that are now invisible for you. I'm using my own applications. If you sum all bytes, this number you need define as your receive buffer in PLC program. Look to that MicroWin help for SMB description and check some needed settings, depended to Freeport.

Hi

I have found 1 application name Ultra Serial Port, It can change ASCII - HEX value. Is that what you means?

And also you said "sum" value, and put that value to PLC memory ? I don't get that. Could you please explain this matter to me ? 

Hello,

yes, also good application. Now you can see also control chars, look to RX message for 0D and 0A. Compare this with some ASCII table, look in web for it. With sum of chars/bytes I mean you need know how much bytes you'll have in receive buffer (memory) when weigh sends data. Simply count that number of bytes. This number (you can also add some bytes value little bit higher for sure) you need set in DB block in buffer definition. In S7-200 look to help with SMB description (sugested before) and also to XMT/RCV instructions. I see now some TX message in your picture, what's that? You need send some message to weigh first for receive data? I see also some RX without TX messages...

Duris_I

Hello,

yes, also good application. Now you can see also control chars, look to RX message for 0D and 0A. Compare this with some ASCII table, look in web for it. With sum of chars/bytes I mean you need know how much bytes you'll have in receive buffer (memory) when weigh sends data. Simply count that number of bytes. This number (you can also add some bytes value little bit higher for sure) you need set in DB block in buffer definition. In S7-200 look to help with SMB description (sugested before) and also to XMT/RCV instructions. I see now some TX message in your picture, what's that? You need send some message to weigh first for receive data? I see also some RX without TX messages...

 Hi, thanks for your reply, I will follow step by step:

1. What byte CR and LF use for ?

2. Now, I see that there are 15 bytes in CAS-CI1560A format, is that right ! ( pls see the attached pic)

3. "This number (you can also add some bytes value little bit higher for sure) you need set in DB block in buffer definition" --> Is that OK if weigh scale send 15 bytes but PLC receive more bytes ( 16, 17...) ???

4. I will study to know more about SMB, XMT, RCV block in S7-200

5. You see some TX message in my pic --> that's just my misoperation, I was trying to know how Ultra Serial Port work , and it's appeared ! Now , I'm just want to how to transmit data to S7-200. I will do it later .

tomorrow or Monday I will make PLC code and try to receive data from weigh indicator and inform to you the result.   , I hope I can do it.

Hello

I'm so happy to infrom you that I have just received data from CAS to S7-200 in FREEPORT mode, the data format same as the CAS datasheet... 

The first step is successfull , and now I will learn how to change this ASCII code to the real and apply to my application, connect to printer. My application is Packing weighing scale

Thanks for your support , if possible I will as for your support if there is any problem with my protocol, connect to printer...

Thanks again

New question published by Silam is split to a separate thread with the subject How can convert String Value to Real?.

Best regards
Jen_Moderator