Hi everyone

I need some advice

I am trying to get a scanner scale to send the weight to my application (I can get the barcode number with no problem)

I was sent this by the Manafactor

Single Cable:
RS232 Parameters:  9600, Odd, 7, 1, (recommended) - No software control
Weight Request:  STX, Address, FC, ETX, BCC
  STX = ASCII S (83 dec, 53 hex)
  Address = ASCII 1 (49 dec, 31 hex)
  FC (function code) = ASCII 1 (49 dec, 31 hex)
  ETX = ASCII CR (13 dec, 0D hex)
  BCC = Optional
Weight Format:  STX, 1, 1, xxxxx, ETX, BCC
Scale Cancel (optional - dependent on POS s/w):  STX, 1, 2, ETX

So working from this I have come up with this code


but I keep getting the Error Mesage "nothing from Scale" print

am I doing something wrong? any help or gidance would be most welcomed

If it is printing "Nothing from scale" then there is no error, i.e. the Read worked.

 So why is the scale not sending the weight?

I have even tried to send the Commands

Write #RS232Scanner, "S11\r"
Write #RS232Scanner, "S14\r"

But the scale still refuses to do anything (the scanner is still sending data to the PoS And this is on the same port)

Because you haven't told us, I have to ask the obvious.

At the line have you inserted a breakpoint and inspected the value of the Global and the value of Global.ScaleData?

b

I have done a print to the debug console and it is empty

 I have no clue but..
I've seen issues using Sleep not Wait.

I've seen issues using CStr() not Str() to get values?
actually, looking at it, the Read command should read to a String variable  
Global.ScaleData should be a string , so CStr() is not needed. CStr converts a non string value to a String,

Does the Write command need a terminating Linefeed?

Are you receiving ANY info from the device using Read? Ie, you are sure the com link is working.

I'd write it like this…

BruceSteers said

I have no clue but..
I've seen issues using Sleep not Wait.

I've seen issues using CStr() not Str() to get values?
actually, looking at it, the Read command should read to a String variable  
Global.ScaleData should be a string , so CStr() is not needed. CStr converts a non string value to a String,

Does the Write command need a terminating Linefeed?

Are you receiving ANY info from the device using Read? Ie, you are sure the com link is working.

Yea I can get the barcodes from the device (it is a combined scanner / scale unit) and it sends the Barcode number out with no problem

BruceSteers said

I'd write it like this…

Code (gambas)

1.  
2. Public STX As String = Chr(&H53)
3. Public Address As String = Chr(&H31)
4. Public FunctionCode As String = Chr(&H31)
5. Public ETX As String = Chr(&H0D)
6.  
7. Public Sub btnRequestWeight_Click()
8.  
9.     Write #RS232Scanner, STX & Address & FunctionCode & ETX
10.  
11.     Wait 0.1  ' wait a little longer
12.      
13.     Try Read #RS232Scanner, Global.ScaleData, Lof(RS232Scanner)
14.    
15.     If Error Then
16.         Print "Error With Incoming Serial Data\n";; Error.Text
17.     Else
18.    
19.       If Global.ScaleData Then
20.         Print "Raw Scale Weight :";; Global.ScaleData
21.         ' CleanUpBarcodeData(CStr(Global.ScannerData))
22.       Else
23.         Print "Nothing from Scale"
24.       Endif ' no data if
25.  
26.     EndIf ' error if
27. End
28.  
29.  

Just tried that and I am sorry to say still nothing coming from the scale

Not sure if this will make a differance but this is my code i am using to open the comport (I asuume it is open to talk both ways)

How about setting up a read handler?

looking at the page /comp/gb.net/serialport - Gambas Documentation it has a number of other Events

Note: the below method is expecting the device to send text strings not binary values.



I'd say your problem is probably either read/write is not set up properly or the command being sent is not the right format.
It's very very difficult for us to guess your problem with tiny snippets of code and none of us having the device you have.

I'd say you need the following..
More study on the differences between vb code and other examples you're finding and gambas code so your conversions look better.

More study on opening/reading/writing/watching streams
a bit more research to find some example code that uses your device. any programming language code should help give insights into the correct operation of the device.

Does it need a LF?
Write #RS232Scanner, STX & Address & FunctionCode & ETX & gb.Lf

Do the commands need to be sent individually?
Write #RS232Scanner, STX
Write #RS232Scanner, Address
Write #RS232Scanner, FunctionCode
Write #RS232Scanner, ETX

You are just going to have to play around with it till you crack it

PS. I do not have a device to test the above code so have no idea if it will work , it's just an example.

@BruceS,  Yes I was going to suggest the same but I still haven't got an answer from AndyGable to my question

At the

Code: Select all

If Len(Global.ScaleData) > 0 Then

line have you inserted a breakpoint and inspected the value of the Global and the value of Global.ScaleData?

AndyGable ,

I have done a print to the debug console and it is empty

is the answer to a different question. Printing something and inspecting something are not the same.

thatbruce said

@BruceS,  Yes I was going to suggest the same but I still haven't got an answer from AndyGable to my question

At the

Code: Select all

If Len(Global.ScaleData) > 0 Then

line have you inserted a breakpoint and inspected the value of the Global and the value of Global.ScaleData?

AndyGable ,

I have done a print to the debug console and it is empty

is the answer to a different question. Printing something and inspecting something are not the same.

Hi thatbruce

the Global.ScaleData is empty nothing is being placed into it

Hoowee. We are really going to have to go back to basics here.

Going back to your original post :
You appear to be setting STX, which I presume is the ANSI "start transmission" character, to &H53. But 53 is the printable "S" character ?
STX is $H02
Any reason for this discrepancy?

Also, according to your "Manafactor" ETX is a "CR" character, &0D which is a bit strange. But if they really mean it then ok.
Their REQUEST string is "Weight Request": STX, Address, FC, ETX, BCC where the BCC is optional (and is a low level and I mean UART level character added to the TX sequence).
So you should be sending (in hex):
02;31;31;0d
of which I find that 0D a bit weird in that why does it need a C/R and no ETX

Can you post a link to that "Manafactor" document.
b

Just to summarise where we are at the moment regarding Gambas.
<LIST>

• <LI>Your program is using a Write command to send a request to the scale.</LI>

</LIST>
<LIST>

• <LI>Your program waits a little while</LI>

</LIST>
<LIST>

• <LI>It then attempts to get the scale's response using a Try Read construct</LI>

</LIST>
Now this read succeeds because it <COLOR color="#FF0000">almost always will*</COLOR>. By using Try Read you are essentially saying "Check for any data in the buffer and if so, stick it in Global.ScaleData". So the command will always work, there will be no error. Thus the "If Error" part will never happen and the "Else" part always will.
<LIST>

• <LI>Your program then tests to see if the Read actually found some data.</LI>

</LIST>
As you say, it doesn't

Hence the above post.

* The only example I can think of is when someone runs away with the scale exactly during your Sleep pause.

thatbruce said

Hoowee. We are really going to have to go back to basics here.

Going back to your original post :
You appear to be setting STX, which I presume is the ANSI "start transmission" character, to &H53. But 53 is the printable "S" character ?
STX is $H02
Any reason for this discrepancy?

Also, according to your "Manafactor" ETX is a "CR" character, &0D which is a bit strange. But if they really mean it then ok.
Their REQUEST string is "Weight Request": STX, Address, FC, ETX, BCC where the BCC is optional (and is a low level and I mean UART level character added to the TX sequence).
So you should be sending (in hex):
02;31;31;0d
of which I find that 0D a bit weird in that why does it need a C/R and no ETX

Can you post a link to that "Manafactor" document.
b

That information I posted on the first page was the document I was sent by Datalogic

i know foe 100% that the scale works as it works with my windows PC and my windows software

This is the full file that was sent by Datalogic

Dual Cable (SASI):
RS232 Parameters:  9600, Even, 7,1 - No Flow Control
Weight Request:  ASCII W (87 dec, 57 hex)
Weight Format: STX, xx.xxx, CR
 
Dual/Single Cable (ICL):
RS232 Parameters:  2400, Even, 7,1 - works with ACK/NAK
Weight Request:
1. Enquire (scale status): ASCII ENQ (05 dec, 05 hex)
Answers:  
Error = NAK
Weight Not Stable = NUL (00 dec, 00 hex)
Weight OK = ACK (06 dec, 06 hex)
2.  Data Request:  ASCII DC1 (17 dec, 11 hex)
Answers:
Error = NAK (05 dec, 05 hex)
Data = STX, Status, xxxxx, BCC, ETX


Single Cable:
RS232 Parameters:  9600, Odd, 7, 1, (recommended) - No software control
Weight Request:  STX, Address, FC, ETX, BCC
  STX = ASCII S (83 dec, 53 hex)
  Address = ASCII 1 (49 dec, 31 hex)
  FC (function code) = ASCII 1 (49 dec, 31 hex)
  ETX = ASCII CR (13 dec, 0D hex)
  BCC = Optional
Weight Format:  STX, 1, 1, xxxxx, ETX, BCC
Scale Cancel (optional - dependent on POS s/w):  STX, 1, 2, ETX
 
To do this in Hyperterminal you need to do it via sending a text file.

So to send STX do an alt function 002,S11,Enter,Alt Function 003

Or do via another program that sends data in Hex

---

test in com test serial single cable option.

send the following command to get weight, then put the weight on.
\x53\x31\x31\x0D
A comtest session is saved in the FRS folder for RS232 SC Host command examples.

send the following command to get weight, then put the weight on.
\x53\x31\x31\x0D

Well i wish you'd posted that in the first post.
I'm not sure what it means but i bet the other Bruce has a pretty good idea after seeing their example of sending the command.
far easier to understand than "what are you doing wrong"

did you try
Write  #RS232Scanner, "\x53\x31\x31\x0D"

 

I'm not sure what it means but i bet the other Bruce has a pretty good idea after seeing their example of sending the command.
far easier to understand than "what are you doing wrong"

Hey man, it took me three whole days to set up the GF's cash register in the pub. The people who write these POS manuals really should be taken out and horsewhipped. This is why I'm trying to go through this step-by-step (and keep asking what seems to be inane questions like what follows).

Andy,
1) What connector types are involved at your computer end here, DB25, DB9, USB, RSJ45, RSJ65?
That may seem a ridiculous question, but DataPoint use different software protocols (at the application message level) for different cables.
2) That file they sent you is self-contradictory and basically looks like something that was thrown together randomly.
a) "Weight Request: STX, Address, FC, ETX, BCC" - Let's assume that is the correct request for your scale and cables.
A bit of a look through a couple of datapoint manuals reveals that the STX character used by the scale is actually <COLOR color="#FF0000">programmable</COLOR>. So we need to find out what is is for the scales in question (or reset them). Also if you look at the schematics of these POS systems you will find that each component has its own processor, IO controller and UARTS in it. So whats good for the barcode scanner may not be the same for the scales (or the display etc). However, lets assume that for your scales the STX character is &H53 (the "S" character). Which

1. makes their

So to send STX do an alt function 002,S11,Enter,Alt Function 003

line bullshit. (But it might be a half-garbled bit of "Hyperterminal" text and so is absolutely useless here.)
c) So looking at a couple of their technical specs it does appear that some, but not all, of their scales do have a default STX value of "S". Sheesh. Some comms programmers need horsewhipping as well.

Can you determine what the STX character really is for your test scales?
Are you trying to program for only one scales model, or multiple. If the latter we are going to have to find out how to query the damn things to get the STX character they are using.

My brain is starting to hurt and we have only looked at one character in the stream    - more later/tomorrow.

b

thatbruce

I totally agree with you on the user manals for Point of sale hardware they are not done very well at all

I have the fun job of converting over from Windows the Printer, Cash drawer and card processing modules (they are NOT going to be fun but I have a example of the cash drawer status support in FreeBASIC) The hard part is going to figure out how the Printer status data

anyway in replay to your requests please see below

1. I am using a DB9
2. That was the only thing I received from Datalogic (I do have access to a C app that was designed to work with the scanner / scale but i'm being told it is not complete

3) Can you determine what the STX character really is for your test scales? I would have to look at the documents and come back to you on that one

4) I am going to use a Module per scale (but Datalogic is saying the wight command should work for all thier Scanner / scales ranges)

My brain is starting to hurt and we have only looked at one character in the stream I am sorry for this your brain is hurting mine is about to melt

Morning Andy,

Another side-ways question: Is there a device access controller (DAC or sometimes EAC, LAC or DCU <COLOR color="#BFFFFF">or even FIIK</COLOR> depending on the POS brand)? Because if so we may need to find out how to talk to it rather than the individual parts.

Regardless of that, good a DB9 connector usually means we are dealing with a fairly basic electronics system. By basic I mean they tend to follow the old serial comms protocols.

… hmmmm thinks

BINGO! I now see what this STX = "S" crapola is all about (and why there is no proper ETX). They are only talking about the message content, but <COLOR color="#FF0000">they are using flow control terms to describe it</COLOR>.  :evil:  :evil:  :evil: Right, the conversation is fundamentally:
Alternatively and not specified is what happens if the item is not put on the scale or … or … or … (We may have an "or" here.)

But assuming everything is tickety-boo. Lets look at what I think they really mean.

The "Weight Request" message sent by the computer in one burst is :
which they have specified as :
Now, we can do all that without resorting to hex at all. Just Write #RS232Scanner, "S11\n" should do it.

(miracle occurs here. The scale figures out it has something on it, measures its weight and sends a message back to the computer.)

The "Weight Format" message you should get is :
and as you implied originally,  that should be just a string of ascii characters. So, if
Read #RS232Scanner, Global.ScaleData, Lof(RS232Scanner) is giving an empty string instead of "S11xxxxx\n" then something is very wrong somewhere.

Let's try something silly…

What happens?

b

Hi thatbruce

I copied your code and I got a error saying End of file in FMain:108 and it is heighlighting the line Line Input #RS232Scanner, Global.ScaleData


*I had to update the Endofline to work with my RS232Scanner steam

This is what I am using to read the barcode from the scanner side


If you know of a better why I am more then willing to see what you would do (best way to learn)

I copied your code and I got a error saying End of file in FMain:108 and it is heighlighting the line Line Input #RS232Scanner, Global.ScaleData

Good! Now we are getting somewhere. It looks like there is nothing in the input buffer as the Line Input is not waiting for some data.

Try this version

*I had to update the Endofline to work with my RS232Scanner steam

Ah, yes. I did wonder whether the static version would work in this situation. Don't forget I'm working blindly here, the only serial device at this location is me, so I can't check the code I'm posting. Also, the code "should be" atomic and you shouldn't have to make changes elsewhere to get it to work. So if other things break, undo it (use a dedicated branch for this stuff and use git revert? (or whatever it is)) and tell me.

Hi thatbruce,

I tired your code and the app just sits there doing nothing if I Step though the code it just sits on the

Line Input #RS232Scanner, Global.ScaleData Line

And yes I had to comment out the loop command otherwise It was just in the loop for ever

<IMG src="https://support.algpos.co.uk/images_help/barcodeReader-incoming.png"> </IMG>
this is just to show you I am getting data from the scanner side (so the scanner/scale is communicating to the Computer)

Woah! Where'd that

  Write #RS232Scanner, "S14\n"

come from?

Sorry according to the C program it was needed (I must have forgotten to remove that before sending it to you)