HT-CM400 NXP Semiconductors, HT-CM400 Datasheet - Page 76

• Manufacturer Part Number: HT-CM400
• Description: Ht Cm400; Ht Rm440 Family; Ht Rm800 Family Interface Protocol Reader - Host
• Manufacturer: NXP Semiconductors

Communication Reader-Host
3.9 Examples to Access HITAG 1 Transponders
In the following please find examples of read/write cycles both for plain and encrypted access in
order to illustrate the command sequence.
3.9.1 Long Range: Anticollision Cycle
In case of several transponders in the reading area of the read/write device the GetSnr command
indicates this by the more byte. To select one of these transponders for following read or write
operations an anticollision cycle must be executed as described in the following flow chart.
*) In case you want to access the same tags for several times.
Htswp.doc/HS
proloc GetSnr (&snr, &more);
proloc GetSnr (&snr, &more);
read or write the selected tag
Long Range-Anticollision-Cycle
proloc HaltSelected ( );
proloc SelectLast ();
proloc HFReset ( );
no
while (!RWDEot);
while (!RWDEot);
while (!RWDEot);
while (!RWDEot);
while (!RWDEot);
RWDErr
RWDErr
RWDErr
RWDErr
START
more
= 1 ?
< 0 ?
< 0 ?
< 0 ?
< 0 ?
no
yes
no
no
no
yes
yes
yes
yes
Page 76 (104)
Rev. 1.0
interpretation
*)
of errors
GetSnr
Select
Read/Write
Halt
GetSnr
Reset all Tags
98-02-10