HID Global Corporation 5553 Manuale Utente

 

HF Multi ISO RFID Reader User Manual, Firmware V1.4 

 

1508-USM-00-0-04 

 

2.3.1.2.6 

LED activity 

The LED stays green as long as a tag was found and goes dark if the tag is removed from the 
field. 

 

This command gives the earliest possible indication that a specified tag has been removed from 
the field 

'dc' 

Timeout byte, Persistence byte, UID 

UID 
'N' 

Specified UID – the tag is still present after the timeout 
The specified tag is no longer in the field 

dc 32 00 04 22 0F 71 4B 1C 80 

04 22 0F 71 4B 1C 80 

Specified tag still present 

dc 32 01 04 22 0F 71 4B 1C 80 

‘N’ 

Specified tag no longer present 

2.3.1.3.1 

Timeout 

This byte specifies the time the reader will check for the (specified) tag being removed from the 
field.  The actual timeout (in mS) is 4 x the Timeout byte, giving a range of 4 – 1000mS.  In 
practice, the granularity of the actual timeout is affected by the Command Guard Time, so an 
accuracy of +/- 5% is achievable. 

If the tag is detected as no longer present before the timeout has been reached, the command 
immediately returns ‘N’. 

2.3.1.3.2 

Persistence 

This parameter specifies the number of times the reader checks that the tag really has been 
removed from the field – an ‘anti-glitch’ measure.  A values of 0 is treated as if it were ‘1’. For each 
integer value greater than 1, the basic test loop is repeated, adding approximately 6mS to the 
timeout period. 

2.3.1.3.3 

UID 

This is the UID of the tag the reader is checking.  It may be 4, 7 or 10 bytes 

 

August 2010 

 

Page 41 of 144 

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