Read and Write Automatically

Hi itzah,

sure you can automatically read and write.

I suggest using the PRESENCE (=TAG in RF field) output of a read/write block to start a state machine like this:

1. Read the transponder.
2. Process the data (or whatever you're doing).
3. Check for OK or NOK.
4. Write result onto the transponder.

That's all. Just implement a state machine which starts after PRESENCE = true (preferably by edge detection of this bit).

Can you specify you're problem? I don't get it.

Do you need a example for a state machine?

What's your preferred programing language? SCL?

Hi,

attached you'll find a screenshot of a short function block which is reading and writing automatically. I think it's an easy to understand example, though it's written in SCL.

In this example I'm using the PRESENCE output of the read block to detect if there's a TAG in field. After edge detection (with R_TRIG block) of PRESENCE I'm starting a state machine ("case of" instruction).

In this state machine I'm automatically reading and writing to TAGs:

• State 0: Wait for a TAG to occur. Do nothing.
• State 1: Read the TAG; Wait for acknowledge ("statReadDone") and move to next state.
• State 2: Write the TAG; Wait for acknowledge ("statWriteDone") and move to state 0.
• State 3: Handle errors.

Underneath the state machine the RFID blocks "Read" and "Write" are called cyclically to be able to set the PRESENCE bit appropriate. The EXECUTE inputs of the RFID blocks are set in the state machine. Note: "Reset" is done by another block independently.

I hope this helps.