Rdr_to_sph_ack – ACS ACR31 Swipe Card Reader User Manual
Page 17
![background image](/manuals/248160/17/background.png)
ACR31 – Reference Manual
Version 1.00
www.acs.com.hk
Page 17 of 19
6.9. RDR_to_SPH_ACK
This acknowledgement message is sent by ACR31 to the mobile device specifying the acceptance of
certain command messages. This message also includes the error code whenever appropriate.
Offset
Field
Size Value
Description
Encrypted
0
bStartByte
1
23h
Message start byte.
No
1
wLength
2
0004h
Number of extra bytes starting
from the next field for this
message.
3
bMessageType
1
82h
4
bErrorCode
1
Specify the error code for the
previously processed command
message.
The possible error codes are
listed in Appendix B.
5
wCheckSum
2
CRC16 checksum for all the
preceding fields.