User's Manual

19
May ’00 Chapter 2. Communications Protocol
2.2.3 Status
The 'Status' byte provides feedback from the preceding read or program operation.
Status Bits Setting Comment
0,1 00 Transponder type: RO
(MSB,LSB)
01 Transponder type: R/W
10 Transponder type: MPT/SAMPT
11 Other
2 1/0 If set, Startbyte detected
3 1/0 If set, DBCC O.K.
4 1/0 If set, FBCC O.K.
5 1/0 If set, Micro-reader S/W version follows
6 - 7 Reserved
2.2.4 Data Field
Response # of Bytes
Type in Data Field Comment
RO 8 Identification Data (LSByte first), 4.2.1
R/W 8 Identification Data (LSByte first)), 4.2.2
MPT/SAMPT 9 Identification Data (LSByte first), plus Read Address, see
4.2.3
Other 14 Complete transponder protocol without pre-bits provided
that a valid RO or R/W start byte was detected
No read 0 No Data Fields, not even transponder start byte was de-
tected, status 03
hex
S/W version 1 For example: 15
hex
means S/W version 1.5
Section 4.2
provides an overview of the response telegrams of the current TIRIS
transponder types.
2.2.5 BCC
The 'BCC' field is a one-byte value of the Longitudinal Redundancy Check calcula-
tion (Xor'ed bytes) for the preceding message. The calculation is performed on the
whole message excluding the Start-Mark. An example is shown in section 2.1.5.