User's Manual

ACR1281S
 Advanced Card Systems Ltd. Page 12 of 56
HARDWARE DESCRIPTION
3. USB Interface
The ACR1281S is connected to a Host through the RS232 Serial Interface; the max speed is up to
500kbps.
Pin Signal Function
1 VCC
+5V power supply for the reader.
2 RXD
The signal from the reader to the host.
3 TXD
The signal from the host to the reader.
4 GND
Reference voltage level for power supply
4. LED Indicator
The LEDs are used for showing the state of the contact and contactless interfaces.The Red LED is
used for showing PICC status and Green LED for ICC.
Reader States Red LED
PICC Indicator
Green LED
ICC Indicator
1. No PICC Found or PICC present but not
activated.
A single pulse per
~ 5 seconds
2. PICC is present and activated ON
3. PICC is operating Blinking
4. ICC is present and activated ON
5. ICC is absent or not activated OFF
6. ICC is operating Blinking