Communication Timing; Default Settings - IDTECH SecureHead User Manual

Where:
<STX> 02h
<S> Indicates setting commands. 53h
<R> Indicates read status commands. 52h
<FuncID> One byte Function ID identifies the
particular function or settings affected.
<Len> One byte length count for the following data
block<FuncData>
<FuncData> data block for the function
<ETX> 03h
<CheckSum> Check Sum: The overall Modulo 2
(Exclusive OR) sum (from <STX> to
<CheckSum>) should be zero.
<ACK> 06h
<NAK> 15h

4.1. Communication Timing

The SecureHead has a 50ms start up period, during this period, it doesn't support communication and
card reading. If the terminal tries to talk to SecureHead during this period, SecureHead may not be
functional until restart.
SecureHead also takes time to process a command. During that processing time, it will not respond to a
new command.
Card swipe actions can interrupt command process, instead of sending command responses,
SecureHead will only send card data.
The typical delay for the reader to respond to a command is 20ms, the maximum delay for the reader to
respond can be as much as 40ms. Caution must therefore be taken to maintain a minimum delay
between two commands.
A minimum delay of 50μs is required between each character send to SecureHead through SPI
interface.
If the noise of working environment interferences the SPI communication, to the level that SecureHead
can't receive commands correctly, SecureHead will restart to reduce the impact. Restart takes 600ms.
Terminal won't get any command response in this situation.

4.2. Default Settings

The SecureHead reader is shipped from the factory with the default settings already programmed. In
the following sections, the default settings are shown in boldface.
For a table of default settings, see Appendix A.
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SecureHead SPI Interface with FPC User Manual
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