What are the Modbus Registers for the RDR-80581AKD-P reader?
In general, the data for the Modbus TCP reader interface is very similar to the EtherNet/IP reader interface. The only real difference is byte ordering within the 16-bit Modbus registers.
Modbus Holding Register Addresses 0 & 1 (2 registers)
- 0 (0x00) = Off – Turn off the LED
- 1 (0x01) = Red – Illuminate the Red LED
- 2 (0x02) = Green – Illuminate the Green LED
- 3(0x03) = Amber – Illuminate both LEDs for Amber
- 255(0xFF) = Allow the reader to automatically control the LED (Red – no card data, Green – valid card data received)
- 1 (0x01) = Short Beep – A short beep is played
- 2(0x02) = Two Short Beeps – a short beep is repeated twice
- 3(0x03) = Three Short Beeps – a short beep is repeated 3 times
- 4(0x04) = Four Short Beeps – a short beep is repeated 4 times
- 5(0x05) = Five Short Beeps – a short beep is repeated 5 times
- 101(0x65) = One Long Beep – a Long beep is played
- 102(0x66) = Two Long Beeps – a long beep is repeated twice
Modbus Input Register Addresses 0-18 (19 registers)
- The number is incremented to indicate a change in ID data and Bit
- Logical Unit ID – Unique Identifier for the Reader (if assigned
during reader configuration)
- In Polling Mode, this value is the total bit count of the incoming
ID. In Listen Mode, this value is 0 when a card is not present, and 1 when a card is present.
- Raw card ID data where bits are “right-aligned”, therefore, the
least significant bit is contained in the least significant bit of Register 18.
For example, if a card contains 24 bits of data 0xB7748A, the Modbus Registers will contain the following data: