PN532 ISO14443-4 communication Issue

[christiangrenie]

Hello,

I'd like to communicate very fast from a PN532 (PICC) device with a PN512 (PCD) Initiator using the ISO14443-4.  I have a lot of data to transfer from PICC to PCD.  Since the PN512 has only 64 bytes in the FIFO, the PN532 uses the chaining mode to transfer 256 bytes.  I use the command 0x8E in PN532 to send 256 bytes and I can see that there're 4 x 64-bytes transmitted from PN532 to PN512.  

I attached an image to show the first 64 bytes transmission.

I'd like to understand why it takes several ms for the PN532 to transmit the first 64 bytes.  Is there a way to improve that?  To reduce the process time to send the first packet?

Please, refer to the image to understand my issue.  I took several days before posting this message.  

Thank you very much!

[christiangrenie]

Hello,

I did a small mistake in the picture.  It takes 9.9 ms to receive (PCD) the first packet.  At 424 kbits per seconds, a 64 bytes should take around ~1.5 ms, but why does the PN532 take 9 ms to send the first packet and also the next ones.  The PN532 firmware version is 1.6.  

I attach a new picture...  

[Kan_Li]

Hi Christian,

Would you please provide more details on the setup regarding PN532 and PN512? Thanks for your patience!

Have a great day,
Kan

[christian_greni]

Hello Mr Kan,

Sorry for this very very long delay.  I was busy on a new project and now, I come back to this issue.  It's really not fixed.  I would like to transfer data as fast as possible but I noticed that the PN532 device sends very slow the data.  What information do you need to understand more the problem? 

I use the PN512 to receive the data and I noticed that it takes more than 10 ms to receive the first 64 bytes packet.  It's too slow when I initialized the speed to 424 kbps.