User's Manual

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2.4 Operating mode 2 - reading triggered by the serial interface
In operating mode 2, the exciter is always turned off. Triggered by the command GT, the exciter is acti-
vated. After successful reading of a transponder number the exciter is turned off automatically.
exciter
processor
interface
reading cycle
ID
GT
Figure 2.4: software triggered reading operation
If the first reading cycle yields no result (NoRead), the on-time of the exciter is limited by the parame-
ter TOR (time out reader): Reading cycles are continuously started until either a transponder is read
successfully or the time span corresponding to the value of the parameter TOR has expired. The reader
will not interrupt the last running readout cycle. If no transponder number has been read, a NoRead is
output.
exciter
processor
interface
TOR
GT
reading process
NoRead
reading cycle reading cycle reading cycle
Figure 2.5: software triggered reading operation with TOR>0
Please note: Within the time span defined by the value of TOR no NoRead will be output on the interface!
3 Protocol format
The command set described in this chapter defines the transfer of data on the serial interface.
The commands consist of a command code and of a parameter value optionally. Commands are termi-
nated by the control character <CR> (13H). The control character terminates the command line.
Command codes and parameters, that means all letters and numerical values, are principally transmitted as
a sequence of ASCII characters (the value 255 (decimal) consequently as 32H, 35H, 35H; the command
RST as 52H, 53H, 54H).
3.1 Echo function
The echo function can be switched on or off.