EL-UHF-RC4 Protocol §

Communication Protocol §

EL-UHF-RC4 can communicate with external application through:

• RS232
• USB
• TCP/IP depending on the reader interfaces.

Serial port communication parameter §

115200 8N1:

• Baud rate: 115200 bps
• 8 data bit
• 1 stop bit
• Without parity check bit

Command §

Command refers to the data packets sent by the external application to the EL-UHF-RC4 module.

Response §

Response refers to the data packets returned by the module to the external application

Data Frame Format §

Status List §

Status code returned by tag:

CRC16 Calculation §

CRC16 is calculated from HEAD to Data[].

#define PRESET_VALUE 0xFFFF
#define POLYNOMIAL  0x8408
 
unsigned int uiCrc16Cal(unsigned char const  * pucY, unsigned char ucX) {
    unsigned char ucI,ucJ;
	unsigned short int  uiCrcValue = PRESET_VALUE;
 
   	for(ucI = 0; ucI < ucX; ucI++) {
        uiCrcValue = uiCrcValue ^ *(pucY + ucI);
        for(ucJ = 0; ucJ < 8; ucJ++) {
            if(uiCrcValue & 0x0001) {
                uiCrcValue = (uiCrcValue >> 1) ^ POLYNOMIAL;
		   	} else {
		    	uiCrcValue = (uiCrcValue >> 1);
		   	}
		}
    }
    return uiCrcValue;
}

In Python:

def calculate_checksum(data: bytes) -> bytearray:
   value = 0xFFFF
   for d in data:
       value ^= d
       for ucJ in range(8):
           value = (value >> 1) ^ 0x8408 if value & 0x0001 else (value >> 1)
   crc_msb = value >> 0x08
   crc_lsb = value & 0xFF
   return bytearray([crc_msb, crc_lsb])
 
 
 
 
HEADER = 0xCF
BROADCAST_ADDRESS = 0xFF
INIT_DEVICE_COMMAND = bytearray([0x00, 0x50])
DATA = bytearray([])
DATA_LENGTH = len(DATA)  # 00
 
 
request_data = bytearray([HEADER, BROADCAST_ADDRESS])
request_data.extend(INIT_DEVICE_COMMAND)
request_data.extend(DATA)
request_data.extend(bytearray([DATA_LENGTH]))  # CF FF 00 50 00
 
 
checksum = calculate_checksum(request_data)  # 07 26
request_data.extend(checksum)
print(' '.join("{:02X}".format(d) for d in request_data))  # CF FF 00 50 00 07 26

Command list §

Inventory Commands §

INVENTORY_ISO_CONTINUE §

This command is the ISO 18000-6C Standard of multi-tag Inventory with anti-collision algorithm.

Command frame:

CFFF0001050000000000F5B5

Response:

Status:

• 0x00 - Inventory successful, Param will contain tag info
• 0x01 - MemBank parameter is wrong, or length is inconsistent
• 0x02 - Command execution failed due to module internal error
• 0x12 - No tag found during inventory, or tag inventory has finished
• 0x17 - Tag Info length exceeds maximum

InventoryParam §

• RSSI - 2Bytes
  • RSSI of the Tag ACK Response
  • Unit: 0.1dBm
  • Encoding: two’s complement format
  • 0xFE48 = -440 = -44 dBm
• Antenna - 1Byte
  • Value: 0x01 for single antenna unit
• Channel - 1Byte
• Tag Info Length - 1Byte
  • Unit: Bytes
• Tag Info - N Bytes

🔗

INVENTORY_ISO_STOP §

Command:

Response:

INVENTORY_ACTIVE §

In active Work mode, the reader will always inventory and send this response as the result of the inventory:

InventoryParam §

• RSSI - 2Bytes
  • RSSI of the Tag ACK Response
  • Unit: 0.1dBm
  • Encoding: two’s complement format
  • 0xFE48 = -440 = -44 dBm
• Antenna - 1Byte
  • Value: 0x01 for single antenna unit
• Channel - 1Byte
• Tag Info Length - 1Byte
  • Unit: Bytes
• Tag Info - N Bytes

Inventory Response Example §

Setting Commands §

MODULE_INT §

Initialize the module. This command is used to confirm whether the module is online.

Command:

Response:

Only STATUS 0x00 si valid.

RESET §

Reset basic module settings to the default values.

Command:

Response:

SET_PWR §

Set RF power (0-30Bm).

Command:

Response:

SET_GET_NETWORK_SETTINGS §

Set/get network parameters (Applicable to LAN)

• Set/Get:
  • 0x01 = Set
  • 0x02 = Get

NetPara:

Command:

Set response:

Get response:

SET_GET_REMOTE_SETTINGS §

Set/get remote network parameters, which is the device (PC, microcontroller, etc) that can receive the data sent from EL-UHF-RC4 Module.

• Set/Get:
  • 0x01 = Set
  • 0x02 = Get

Netpara:

Command:

Set response:

Get response:

GET_DEVICEINFO §

Get the device/module version and SN.

Command:

Response:

Field decription:

SET_BASIC_SETTINGS §

Set module basic parameters.

Command:

• ADDR is the current module address that is being targetted by this command.

BASIC_SET Field §

Total: 25Bytes:

• Addr - 1Byte
• Resv - 1Byte - 0x01
• Work mode - 1Byte
• Interface - 1Byte
• Baud rate - 1Byte
• WG - 1Byte
• Resv - 1Byte - 0x01
• RFID Freq - 8Bytes
• RF Power - 1Byte
• MemBank - 1Byte
• QValue - 1Byte
• Session - 1Byte
• Acs Addr - 1Byte
• Acs Data Len - 1Byte
• Filter Time - 1Byte
• Trigger Time - 1Byte
• Buzzer Time - 1Byte
• Polling Interval - 1Byte

🔗

Response:

• STATUS
  • 0x00 - Successful
  • 0x01 - Parameter error

GET_BASIC_SETTINGS §

Get module basic settings.

Command:

Response:

BASIC_SET Field §

Total: 25Bytes:

• Addr - 1Byte
• Resv - 1Byte - 0x01
• Work mode - 1Byte
• Interface - 1Byte
• Baud rate - 1Byte
• WG - 1Byte
• Resv - 1Byte - 0x01
• RFID Freq - 8Bytes
• RF Power - 1Byte
• MemBank - 1Byte
• QValue - 1Byte
• Session - 1Byte
• Acs Addr - 1Byte
• Acs Data Len - 1Byte
• Filter Time - 1Byte
• Trigger Time - 1Byte
• Buzzer Time - 1Byte
• Polling Interval - 1Byte

🔗

SET_GET_FILTER §

Controls the Tag filter settings, this device can filter the tags by data mask and/or access password

Command:

Set response:

Get response:

Param:

• Command get or set - 1Byte
  • 0x01 - Set
  • 0x02 - Get
• Enable access password filter - 1Byte
  • 0x00 - Disabled (Default)
  • 0x01 - Enabled
• Access password filter - 4Bytes
  • Default: {0x00, 0x00, 0x00, 0x00}
• Enable mask filter - 1Byte
  • 0x00 - Disabled (Default)
  • 0x01 - Enabled
• Start address - 1 Byte
  • The starting address of the memory that is being matched with the mask
  • Default: 0x00
• Mask length - 1Byte
  • Value range: [0, 12]
• Mask data - 12Bytes
  • If mask is less than 12Bytes, fill the rest of the field with 0x00
  • Default: {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
• Filter setting - 1Byte
  • 0x00 - Access password or mask match (Default)
  • 0x01 - Access password and mask match

SET_GET_IO_SETTINGS §

Command:

Get Response:

Param:

• Command get or set - 1Byte
  • 0x01 - Set
  • 0x02 - Get
• Automatic Relay Enabled - 1Byte
  • 0x00 - Disabled (Default)
  • 0x01 - Enabled
• Automatic Relay Time - 1Byte
  • Unit: seconds
  • Default value: 0x03
• Trigger Enabled - 1Byte
  • 0x00 - Disabled (Default)
  • 0x01 - Enabled
• Trigger Level - 1Byte
  • 0x00 less than 0.5V triggers inventory
  • 0x01 higher than 2V triggers inventory (Default)
• Buffer Enabled - 1Byte
  • 0x00 - Disabled (Default)
  • 0x01 - Enabled
• Reserved - 12Bytes

  • [0x00] * 12

OPEN_CLOSE_RELAY §

Manually open or close relay regardless of the automatic relay caused by inventory. It is recommended to use this while disabling the automatic relay setting in the SET_GET_IO_SETTINGS.

Command:

• Option - 1Byte
  • 0x01 - Open
  • 0x02 - Close
• ValidTime - 1Byte
  • Unit: seconds
  • 0x00 - The relay will always be set as the option selected
  • 0x01 - The relay will be set for 1 seconds
  • 0x02 - The relay will be set for 1 seconds
  • and so on..

Response:

BASIC_SET §

BASIC_SET is a 25 bytes of field to be used in SET_BASIC_SETTINGS and GET_BASIC_SETTINGS command.

BASIC_SET Field §

Total: 25Bytes:

• Addr - 1Byte
• Resv - 1Byte - 0x01
• Work mode - 1Byte
• Interface - 1Byte
• Baud rate - 1Byte
• WG - 1Byte
• Resv - 1Byte - 0x01
• RFID Freq - 8Bytes
• RF Power - 1Byte
• MemBank - 1Byte
• QValue - 1Byte
• Session - 1Byte
• Acs Addr - 1Byte
• Acs Data Len - 1Byte
• Filter Time - 1Byte
• Trigger Time - 1Byte
• Buzzer Time - 1Byte
• Polling Interval - 1Byte

Addr §

Addr is the new module IP Address, ranges from 0x00 to 0xFE.

Work mode §

• 0 - Answer mode
• 1 - Active mode
• 2 - Trigger mode

Interface §

• 0x80 - RS232
• 0x20 - RJ45

Baud rate §

• 0 - 9600 bps
• 1 - 19200 bps
• 2 - 38400 bps
• 3 - 57600 bps
• 4 - 115200 bps

WG §

• 1 Byte of Wiegand parameter:
  • Bit7
    • 0 - close WG output
    • 1 - open WG output
  • Bit6
    • 0 - wg26
    • 1 - wg34
  • Bit5
    • 0 - low bit first
    • 1 - high bit first
  • Bit4 - Bit0
    • Reserved

RFID Freq §

• 8 Bytes of RFID Frequency parameter:

  • 1Byte - Region
    • 0x00 - User defined
    • 0x01 - US [902.75~927.25]
    • 0x02 - Korea [917.1~923.5]
    • 0x03 - EU [865.1~868.1]
    • 0x04 - JAPAN [952.2~953.6]
    • 0x05 - MALAYSIA [919.5~922.5]
    • 0x06 - EU3 [865.7~867,5]
    • 0x07 - CHINA_BAND1 [840.125~844.875]
    • 0x08 - CHINA_BAND2 [920.125~924.875]
  • 4Bytes - Frequency Min defines the integer and decimal part of the frequency start, for example for 920.125 MHz:
    • 2Bytes - Integer part, example:
      • 0x0398 - 920 MHz
    • 2Bytes - Decimal part, example:
      • 0x007D - 0.125 MHz
  • 2Bytes - Frequency Step defines the width of each frequency channel
    • 0x7D - 0.125 MHz
  • 1Byte - Channel Number

• Frequency calculation

  • Min Freq = {Frequency Min}
  • Max Freq = {Frequency Min} + {Channel Number} * {Frequency Step}

• Calculation formula for each frequency region

  • Chinese band2： Fs = 920.125 + CN * 0.25 (MHz) CN∈[0, 19]。
  • US band： Fs = 902.75 + CN * 0.5 (MHz) CN∈[0,49]。
  • Korean band： Fs = 917.1 + CN * 0.2 (MHz) CN∈[0, 31]。
  • EU band: Fs = 865.1 + CN*0.2(MHz) CN∈[0, 14]。
  • Ukraine band: Fs = 868.0 + CN*0.1(MHz) CN∈[0, 6]。
  • Peru band： Fs = 916.2 + CN*0.9(MHz) CN∈[0, 11]。
  • Chinese band1： Fs = 840.125 + CN * 0.25 (MHz) CN∈[0, 19]。
  • EU3 band： Fs = 865.7 + CN * 0.6(MHz) CN∈[0, 3]。
  • US band3： Fs = 902 + CN * 0.5 (MHz) CN∈[0,52]。
  • Taiwan band： Fs = 922.25 + CN * 0.5 (MHz) CN∈[0,11]。

RF Power §

RF power of the module, range: [0, 30]

MemBank §

Memory Bank to be read during Inventory

• 0x01 - EPC (Default)
• 0x02 - TID
• 0x03 - User

QValue §

Q-parameter - Default: 0x04 - Range: [0, 15]

Session §

• Session - The session value used when querying the EPC tag
  • 0x00 - S0 (default)
  • 0x01 - S1
  • 0x02 - S2
  • 0x03 - S3

Acs Addr §

• Address of the memory bank being read during tag inventory
  • Unit: Byte
  • Default value: 0
  • When accessing the EPC memory, 0x00 indicates the starting address of the EPC number segment of the EPC area without the CRC and PC segment

Acs Data Len §

• Acs Data Len - Length of data in memory bank to be read during inventory
  • Unit: Byte

Filter Time §

Filters tag with the same data so it will only returned once for the duration of the filter time

• Unit: seconds
• Default value: 0 (No filter)

Trigger Time §

The duration of inventory after the trigger signal is stopped - Unit: seconds - Value range: [0, 255] - Default: 1

Buzzer Time §

The duration of buzzer when the reader finds tag - Unit: 10ms - Value range: [0, 255] - Default: 1 - 0 - Buzzer off

Polling Interval §

Inventory interval - Unit: 10ms - Value range: [0, 255] - Default: 1