MagTek MT-215 TTL SINGLE HEAD, 3-TRACK - Manual (Page 15)

Section 2. Installation
9
TIMING FOR DATA AND STROBE
Figure 2-4 shows the timing when a card is inserted or withdrawn.
Figure 2-4. Timing for Card Present, Data, and Strobe
Card Present
The Card Present signal is low when a recorded card is being moved across the read head. The
Card Present signal is gated with the back sensor to ensure that Card Present will go high when
the card is fully inserted into the Reader.
Data
The Data signal is valid while the Strobe is low. If the Data signal is high, the bit is a zero.
Strobe
The Strobe signal indicates when Data is valid. It is recommended that Data be loaded by the
user with the leading edge (negative) of the Strobe.
NOTES
1. TIME OUT OF THE CARD PRESENT SIGNAL OCCURS
APPROXIMATELY 150 MS AFTER THE LAST STROBE TRANSITION.
2. DATA IS VALID 1.0
μS (MINIMUM) BEFORE THE NEGATIVE EDGE OF
STROBE.
3. 6 OR 7 HEAD FLUX REVERSALS ARE IGNORED FOR LOW DENSITY
CONFIGURATION AND 14 OR 15 FOR HIGH DENSITY
CONFIGURATION.
0
1 1
0 0 0 0 0
DATA
0 0
1 1 1
BIT
TIME
STROBE WIDTH
APPROXIMATELY
25-50% OF BIT TIME
NOTE 3
STROBE
NOTE 1
INTERNAL
CARD PRESENT
NOTE 2