User's Manual

708UM0210-01 October 1999 Autotag-P User Manual Page: 16 of 33
will power down. Coming back into range will reinitiate the entire communication
sequence.
4.5. Communication Protocol Options
There are four communications options available:
Wiegand – 34 or 26 Bit
Clock&Data – 10 or 8 Digit BCD
RS-232 – Autotag-P Point-to-point Protocol
RS-485 – Nortech Multi-drop Protocol
There are two basic communication models either the 708FT023X models or the 708FT024X models (where ‘X’
is the power supply option)
The 708FT023X models have the “RS-232 Autotag-P Point-to-point Communication Protocol”. Where as
the 708FT024X models have “RS-485 – Nortech Multi-drop Communication Protocol”
The 708FT023X models come standard with both Wiegand and Clock&Data communications protocols.
The selection between either Wiegand or Clock&Data is via DIP Switch SW1-3
Other communication protocols are available on special request.
4.5.1 Wiegand Communication Protocol
Refer to section 5.3.1 for switch locations and settings.
This is a unidirectional protocol (from the Autotag-P Base Station to the Access Controller).
One of two versions of this protocol can be selected. Either 34 bit or 26 bit Wiegand. The default is 34 bit
Wiegand. To select 26 bit Wiegand switch OFF switch SW2-2. To revert back to 34 bit Wiegand switch ON
switch SW2-2.
For 34 bit Wiegand Protocol (SW2-2 and SW2-3 ON), (being the preferred version of this protocol). The 32 bit
unique code from the Autotag-P Tag is sent out with the addition of two parity bits
For the 26 bit Wiegand protocol (SW2-2 OFF and SW2-3 ON). The 32 bit unique code from the Autotag-P Tag
has the eight most significant bits striped off and the resultant 24 bits are sent out with the addition of two parity
bits
4.5.2 Clock&Data Communication Protocol
Refer to section 5.3.1 for switch locations and settings.
This protocol is also known as “Magnetic Stripe Track 2.”
This is a unidirectional protocol (from the Autotag-P Base Station to the Access Controller).
One of two versions of this protocol can be selected. Either 10 digit or 8 digit Clock&Data. The default is 10 digit
Clock&Data. To select 8 digit Clock&Data, switch OFF switch SW2-2. To revert back to 10 digit Clock&Data
switch ON switch SW2-2.
For 10 Digit Clock & Data Protocol (SW2-2 ON and SW2-3 OFF), (being the preferred version of this protocol).
The 32 bit unique code from the Tag is converted to 10 digit BCD. Each BCD digit gets its own parity bit. The
resultant digits together with a message header and footer are used to calculate the message check digit.
For 8 Digit Clock & Data protocol (SW2-2 OFF and SW2-3 OFF). The 32 bit unique code from the Tag is
converted to 10 digit BCD. The two most significant BCD digits are discarded. Each of the remaining eight BCD