![background image](http://html1.mh-extra.com/html/datacard/cp80-plus/cp80-plus_service-manual_3691139051.webp)
CP80 and CP80 Plus Service Manual
2-37
Type-A Card Modulation
The type of return modulation from the card to the reader differs with the two
classes of cards (Type-A and Type-B). Type-A cards use a simple On-Off-Keying
modulation (OOK). This is the binary equivalent of amplitude modulation. The
card switches the resistance seen by the card reader at a frequency of 1/16
th
the
frequency of the carrier signal. This means that during a modulation period, the
carrier signal is attenuated every eight cycles. The data stream is even slower
than this (1/128
th
of the carrier frequency) so each data bit will have several
transitions from modulation to non-modulation of the carrier.
Type-B Card Modulation
A Type-B card uses a combination of amplitude modulation and phase
modulation, called Binary Phase Shift Keying (BPSK). This method sends a
constant subcarrier frequency of 847 kHz using amplitude modulation, but shifts
the phase of the subcarrier by 180 degrees (inverted) at each data transition. In
other words, the carrier is always modulated with the subcarrier, but during data
transitions, the subcarrier signal is altered (inverted). The subcarrier is permitted
to invert only at its own transition points (which is why the frequencies are even
multiples of each other).
Содержание CP80 Plus
Страница 1: ...Datacard CP80 and CP80 Plus Card Printers Service Manual May 2007 Part No 539490 002 Rev C ...
Страница 14: ...1 4 Introduction ...
Страница 17: ...CP80 and CP80 Plus Service Manual 2 3 Print Engine Functional Block Diagram ...
Страница 18: ...2 4 Theory of Operation Laminator Functional Block Diagram ...
Страница 22: ...2 8 Theory of Operation LCD Service Mode Menu Diagram ...
Страница 52: ...2 38 Theory of Operation ...
Страница 158: ...6 6 Removal and Replacement Print Engine Front Wire Routing Diagram ...
Страница 159: ...CP80 and CP80 Plus Service Manual 6 7 Print Engine Duplex and Printhead Wire Routing Diagram ...
Страница 160: ...6 8 Removal and Replacement Laminator Front Wire Routing Diagram ...
Страница 161: ...CP80 and CP80 Plus Service Manual 6 9 Laminator Rear Wire Routing Diagram ...
Страница 162: ...6 10 Removal and Replacement Power Supply Wire Routing Diagram ...
Страница 163: ...CP80 and CP80 Plus Service Manual 6 11 Print Engine Cable Connection Diagram ...
Страница 164: ...6 12 Removal and Replacement Laminator Cable Connection Diagram ...