Interface Barcode reader signal with PLC

[shanvis]

Can anybody guide on how to interface a Barcode signal into a PLC. Is it through RS232 communication?

 

[Pierre]

Can anybody guide on how to interface a Barcode signal into a PLC. Is it through RS232 communication?

The PLC you use should have some communication function for its serial port, specifically something like RECEIVE.

Set it up and you will get some ASCII values in HEX.

The barcode reader must be setup to read the specific barcode type.


You must then parse them values to make out the real value read bar your device.

First start with the Receive function and have read the serial data then you will be able to figure out whats coming in.

Since you have never used this stuff, trial and error is much educative.

 

[dalem]

I might have an example, if you were using an AB PLC5. Actually 2 examples. one was through RS232, the other is now being inputted into std I/O cards. (24vdc inputs and outputs.) The barcode hardware was changed, thus the input methond changed.

 

[parky]

Most bar code scanners use 232/485, they have simple ASCII protocols i.e. they will send STX(002) then the barcode then ETX(010) it's that simple(well some may have prog address as well).
Have implemented a number of systems using siemens, AB, mitsi all have 232 comms boards available.
Just done a dual one on Mitsit FX2N using the 232BD board (fits on the PLC at £90.00 it's a snip) & the other port used 232IF module.