Help please~ related to barcode scanner and PLC

[qingtian28]

Hello there, appreciate if someone kind enough to teach me or show me how to solve this problem. Realy headache with this.. Thanks!! =)

I'm currently using a Delta plc model DVP-14ES, and i wanted to ask whether is this model of PLC can read signal from a database as an input?

for example,
when i write a barcode of "A12345" in a programming software such as visual basic or microsoft excel, and then i wanted to send the signal "1&2" to my plc to operate an output.

in short, i want to read the signal from barcode after it is scanned with a scanner..

 

[Lancie1]

I'm currently using a Delta plc model DVP-14ES, and i wanted to ask whether is this model of PLC can read signal from a database as an input?

No, many PLC brand-and-models would be able to read data from an external Visual Basic or Microsoft Excel database, but this data WILL NOT be seen "as an input".

If you have PLC inputs, then use them directly to operate PLC outputs, then also save these same inputs to your historical database. Then there is no ambiguity and less complexity.

In short, I want to read the signal from barcode after it is scanned with a scanner..

This is not the same thing as you described previously. There are many barcode scanners that have the capability of sending barcode labels directly to PLC communications instructions.

Your Delta plc model DVP-14ES has an RS-232 Modbus communications port, which could be used with a barcode scanner that has a RS-232 output.

Here is an example using a Allen-Bradley SLC 504 PLC RS-232 Comm Port. The ARL (ASCII Read Line) instruction reads the barcode scanner input on PLC Comm Port 0. The COP Copy instruction on Rung 008 copies the barcode data to a PLC Character-String memory file.

 

[qingtian28]

Hi lancie, let me tell u my situation, i think it will be easier for u..

When i scan the barcode on an item, and then the item is to be sent to a 3x3 rack. Then the computer which the scanner is commected send a signal to my plc..
Let say this item has to be placed in 2nd row, 3rd column, so i need to use a signal to bypass the sensor before reaching tht posiition, or to energised the solenoid valve..

What is the method i should use? Or is there any way for my plc to receive tht signal??
Thank you in advance.. If u're not understand pls ask me agn, i reali need ur help.. Thank u..

 

[Lancie1]

Then the computer which the scanner is commected send a signal to my plc..

No, this is the WRONG way to do it. Your PLC should be the primary brain (computer is a helper or operator control station). Your PLC should receive the barcode and perform operations to determine where each item is routed.

Or is there any way for my plc to receive tht signal??

Yes, there is and that is what you need to do - send barcode to the PLC.

 

[qingtian28]

Okay, but how to do that? I'm so sorry to cause u trouble..
But i really dont have any idea how to do it..
What function should i used to program it??

Another thing, can i communicate vba excel with plc?

 

[Lancie1]

But i really dont have any idea how to do it..
What function should i used to program it??

See the ladder logic program excerpt that I posted in this thread, Post #2. I used the ARL function to read the barcode scanner data into the PLC.

Another thing, can i communicate vba excel with plc?

It will be much easier to send PLC data to an Excel Spreadsheet CSV file (than it is to send Excel file to the PLC).

 

[qingtian28]

What if i used vba excel to send the signal??
Is it possible??
Jz to be sure if my plc software doesnt have the arl, then wat should i do??

 

[Lancie1]

What if i used vba excel to send the signal??
Is it possible??

I do not know if it is possible. I can see where you might write a Macro Excel command to run a VBA routine to have an Excel spreadsheet send data to your PLC. However, Excel is not really designed for that purpose, and I think it would be very cumbersome to do it that way. What command would you use to tell Excel "now send this value in Excel Cell XY for T seconds to PLC memory location A"? It seems that you would need to have Excel open and running all the time, and be able to issue an Excel Macro keystroke command to send the signal. That will not work very well to move a conveyor barcode signal to your PLC at the right times. I don't think Excel will be able to read a barcode, make decisions, and based on those decisions then issue the proper commands to your PLC.

Your PLC needs to read and respond to the barcode WHEN IT OCCURS, not after it has been moved to an Excel spreadsheet, then retransmitted (by a human-assisted command) to your PLC.

You are going down the wrong path. Look at Barcode scanner-->PLC-->Computer, not Barcode scanner-->Computer-->PLC.

 

[qingtian28]

Ohh.. I got wat u mean..
Thank u man!!
Btw, i'm using WplSoft, and i think i dont have the ARL thing..
Bcoz i've mention, i'm using a delta DVP-14es plc

 

[Lancie1]

By the way, I'm using WplSoft, and I think I don't have the ARL thing.
Because I've mentioned, I'm using a Delta DVP-14ES plc.

Your Delta sofware will have some method or instruction to read an ASCII string from a PLC input port into PLC memory. It probably will have a different name, but it will perform the same function. Look for this instruction in your Delta software user manual.

 

[qingtian28]

I'm sorry again to be such a troublesome person..
Even if i manage to find it, i'm afraid i dont know how to programmed it..
Haihhh..
Is there any related post for it here?? Lolss

 

[Lancie1]

Even if I manage to find it, I'm afraid I don't know how to programmed it.

Do not stop because you do not have knowledge about some subject. You can learn, then you will know how to do it. Read and study your user manuals. If you do not have manuals, search the Internet and find copies that you can save to your computer.

I do not know how to program the Delta to read barcodes, but I know that I could get the manual and figure it out in a few hours. But that would not help you very much, and it would not help me because I do not use Delta PLCs.

 

[qingtian28]

Okok.. Thanks man..
I've caused u alot of prob..
I'll come back to u again if i'm stuck alright??
Hahaha.. Thanks!!

 

[Lancie1]

Is there any related post for it here?? Lolss

Yes, there are 3 or 4 posts about using Delta PLCs. Here are links to those posts. Some of these posts have links to other Delta PDF files that could be useful for you. See Post #15 in the second link. The Delta instructions MODRW and DTM seem to be the keys.

http://www.plctalk.net/qanda/showthread.php?t=47697&highlight=Delta

http://www.plctalk.net/qanda/showthread.php?t=51474&highlight=Delta+plc

http://www.plctalk.net/qanda/showthread.php?t=69120

http://www.plctalk.net/qanda/showthread.php?t=70619&highlight=Delta

 

[qingtian28]

In the pic u sent me in post #2,
What EN,DN,ER represent??