RFID Reader Integration Manual
Comprehensive documentation covering serial communication setup, antenna configuration, tag encoding operations (EPC Gen2 / ISO 18000-6C), and power management. Includes examples for multi-antenna deployments and high-speed inventory scanning.
Serial Communication Setup
Nextwaves NRN protocol RFID readers communicate via serial port (RS-232 or USB-to-Serial). Connection parameters must be configured correctly to ensure stable data transmission.
For browser-based WebSerial API connections, use Nextwaves Reader Connect at app.nextwaves.com/reader. The application auto-detects COM ports and configures connection parameters.
// Request serial port access
const port = await navigator.serial.requestPort();
await port.open({
baudRate: 115200,
dataBits: 8,
stopBits: 1,
parity: "none",
flowControl: "none",
bufferSize: 4096,
});
// Get reader/writer streams
const reader = port.readable.getReader();
const writer = port.writable.getWriter();import serial
port = serial.Serial(
port="/dev/ttyUSB0", # Linux/macOS
# port="COM3", # Windows
baudrate=115200,
bytesize=serial.EIGHTBITS,
stopbits=serial.STOPBITS_ONE,
parity=serial.PARITY_NONE,
timeout=2.0,
)
# Flush buffers before communication
port.reset_input_buffer()
port.reset_output_buffer()Nextwaves NRN Protocol Frame Structure
Every NRN protocol command is encapsulated in a binary frame consisting of: Header (0x5A), PCW (Protocol Control Word), Category, MID (Message ID), Length, Data payload, and CRC16-CCITT checksum.
Command Examples
TX -> 5A 00 01 01 00 00 00 DC E5
+----+ +------+ +----+ +----+ +------+ +------+
| 5A | | 0001 | | 01 | | 00 | | 0000 | | DCE5 |
+----+ +------+ +----+ +----+ +------+ +------+
HDR PCW CAT MID LEN CRC16TX -> 5A 00 01 02 10 00 00 04 5A
HDR PCW CAT MID LEN CRC16
Response notifications (PID 0x1231) contain:
- Antenna ID (1 byte)
- RSSI value (1 byte, raw ADC 0-255)
- EPC data (12+ bytes)
- Frequency channel index (1 byte)TX -> 5A 00 01 02 FF 00 00 88 5A
HDR PCW CAT MID LEN CRC16Key Commands Reference
Antenna Configuration
RFID readers support up to 32 antenna ports. Each port is enabled or disabled via a 4-byte bitmask. Antennas are numbered 1 to 32, with each bit corresponding to a port.
Antenna Bitmask
TX -> 5A 00 01 02 03 00 04 0F 00 00 00 E1 EF
+-----------+
Payload: |0F 00 00 00| <- bitmask
+-----------+
Bit 0 = ANT1, Bit 1 = ANT2, Bit 2 = ANT3, Bit 3 = ANT4
0x0F = 0b00001111 -> all 4 ports enabledMulti-Antenna Deployment
When deploying multiple antennas, consider polarization (linear vs. circular), spacing between antennas, and overlapping coverage zones. The reader scans sequentially through enabled antennas, and each tag report includes the antenna ID for position determination.
Dock Door
2-4 antennas per portal, circular polarization, 30 dBm power
Conveyor Belt
1-2 antennas per station, linear polarization, 20-25 dBm
Retail Shelf
Near-field antennas, low power 15-20 dBm, high density
Tag Encoding (EPC Gen2 / ISO 18000-6C)
UHF RFID follows the EPC Gen2 standard (ISO 18000-6C). Each tag has 4 memory banks: Reserved (passwords), EPC (96+ bit identifier), TID (immutable chip ID), and User (custom data).
Tag Memory Structure
SGTIN-96 Decoding Example
SGTIN-96 is the most common encoding for retail and supply chain products. Convert a 24-character hex EPC into GTIN-14, serial number, and GS1 Digital Link.
EPC Hex: 3034257BF7194E4000001A85
Decoded:
Header: 0x30 (SGTIN-96)
Filter: 1 (Point-of-Sale)
Partition: 5
Company Prefix: 0614141
Item Reference: 812345
Serial: 6789
GTIN-14: 80614141123458
Digital Link: https://id.gs1.org/01/80614141123458/21/6789// NRN protocol WRITE_EPC_TAG command
TX -> 5A 00 01 02 11 00 0C [EPC_DATA_12_BYTES] [CRC16]
// The reader will:
// 1. Select the tag in its field
// 2. Write the provided EPC data to Bank 01
// 3. Return success/failure notification
// Access password required if tag is locked:
TX -> 5A 00 01 02 11 00 10 [ACCESS_PWD_4B] [EPC_DATA_12B] [CRC16]Use the online EPC Encoder tool at /tools/tds-rfid-converter to encode and decode SGTIN-96, SSCC-96, GRAI-96 directly in your browser.
Power Management
Reader transmit power is adjustable from 0 to 33 dBm per antenna port. Higher power increases read range but also increases interference and power consumption.
TX -> 5A 00 01 02 01 00 04 1E 1E 1E 1E 67 FE
+-----------+
Payload: |1E 1E 1E 1E|
+-----------+
0x1E = 30 decimal = 30 dBm per port
Power guidelines:
- 33 dBm - Maximum range (~10m), dock doors
- 30 dBm - Standard range (~6-8m), general use
- 25 dBm - Medium range (~3-5m), conveyor belts
- 20 dBm - Short range (~1-2m), point-of-sale
- 15 dBm - Near-field (~0.5m), shelf readersRSSI Monitoring
RSSI (Received Signal Strength Indicator) values from tags are reported as raw ADC bytes (0-255). Use the conversion formula to get accurate dBm values.
High-Speed Inventory Scanning
For high-speed inventory scanning, configure working frequencies, duplicate tag filter, and continuous scan mode. Readers support up to 700 tags/second with optimal configuration.
Frequency Configuration
UHF RFID operates in the 920-925 MHz band (Southeast Asia), with 0.5 MHz channel spacing. Channels are numbered from 0 (920 MHz) to 10 (925 MHz).
TX -> 5A 00 01 02 05 00 06 00 02 04 06 08 0A C4 1B
Channel mapping (formula: 920.0 + index x 0.5 MHz):
Ch 0 -> 920.0 MHz
Ch 2 -> 921.0 MHz
Ch 4 -> 922.0 MHz
Ch 6 -> 923.0 MHz
Ch 8 -> 924.0 MHz
Ch 10 -> 925.0 MHzOptimal Scanning Workflow
Configure antenna ports and power levels
Set working frequencies (FHSS for dense environments)
Configure duplicate filter (500ms-3000ms depending on use case)
Send READ_EPC_TAG to start continuous inventory
Process tag notifications (PID 0x1231) as they arrive
Send STOP_INVENTORY when done
// 1. Enable antennas 1-4
await sendFrame("CONFIGURE_ANTENNA_ENABLE", [0x0F, 0x00, 0x00, 0x00]);
// 2. Set power to 30 dBm on all ports
await sendFrame("CONFIGURE_READER_POWER", [0x1E, 0x1E, 0x1E, 0x1E]);
// 3. Set working frequencies
await sendFrame("SET_WORKING_FREQUENCY", [0, 2, 4, 6, 8, 10]);
// 4. Set duplicate filter to 1000ms
await sendFrame("SET_FILTER_SETTINGS", [0x03, 0xE8]);
// 5. Start inventory
await sendFrame("READ_EPC_TAG");
// 6. Process tags...
reader.on("tag", (tag) => {
const rssiDbm = -100 + Math.round((tag.rssi * 70) / 255);
console.log(`EPC: ${tag.epc}, Ant: ${tag.antenna}, RSSI: ${rssiDbm} dBm`);
});
// 7. Stop when done
await sendFrame("STOP_INVENTORY");