Incorrect received bytes from PD

[PavletsovGIT]

Hi all,
I am writeing C program for CP, as a PD I use cardreader Dahua DHI-ASR2201A-D. About problem: After initialization pd list by libosdp cardreader reply me correct bytes order. But every time when I try to read card cardreader send my not correct bytes order. After first time card read I get bytes 0x42 0x45 instead of Mark-byte 0xFF.
I thuoght that its trash bytes so I shift bytes left when I receive messages, but libosdp writes error "Incorrect CRC". Also, I thought that I need to change bits order from little-endian to big-endian, but it's not helpful. If error in bits order I could see byte 0xCA (reverse SOM-byte 0x53) in byte order.

Examples bytes order from debug:
Initialization by libosdp:

RS-485: func: cp_send; Sended buf:
[ FF 53 01 09 00 04 61 00 
  60 23 ]
RS-485: func: cp_send; Sended buf:
[ FF 53 02 09 00 04 61 00 
  80 ED ]
RS-485: func: cp_send; Sended buf:
[ FF 53 03 09 00 04 61 00 
  20 A8 ]
...
RS-485: func: cp_send; Sended buf:
[ FF 53 7C 09 00 04 61 00 
  BF 28 ]
RS-485: func: cp_send; Sended buf:
[ FF 53 7D 09 00 04 61 00 
  1F 6D ]
RS-485: func: cp_send; Sended buf:
[ FF 53 7E 09 00 04 61 00 
  FF A3 ]

Received bytes from PD after initialization:

RS-485: func: cp_recv; Received buf:
[ FF 53 81 14 00 04 61 00 
  60 23 00 00 00 00 00 00 
  00 00 00 00 00 00 00 00
        00000000
  00 00 00 00 00 00 00 00 
  ]

Received bytes after first time card read:

RS-485: func: cp_recv; Received buf:
[ 45 42 53 52 38 01 00 00 
  00 00 00 01 08 8A F9 A6 
  00 0C 01 40 01 00 00 00 
  00 00 00 00 00 00 00 00 
  00 00 00 00 00 00 00 00
        00000000
  00 00 00 00 00 00 00 00 
  ]
 OSDP: ERROR: PD[1]: PHY: Invalid SOM 0x45

Received bytes after second time card read:

RS-485: func: cp_recv; Received buf:
[ 00 85 B3 EF 00 00 37 A6 
  00 0C 01 40 01 00 00 00 
  00 00 00 00 00 00 00 00
  		00000000
  00 00 00 00 00 00 00 00 
  ]
OSDP: ERROR: PD[2]: PHY: Invalid SOM 0x00

[sidcha]

I am not sure if I understand your messages correctly. Did LibOSDP initialize properly and come online, and then the card read data is messed up?

• Can you post the debug logs from LibOSDP without any modifications?
• Also, can you please run a later version of LibOSDP (using a VM maybe?)