---
title: "Interfacing RFID reader with Raspberry Pi4"
space: "Wiki"
url: "https://www.sapconinstruments.com/wiki/interfacing-rfid-reader-with-raspberry-pi4"
updated: "2026-10-18"
---

Command list Available for UHF RFID reader IDT-112R


```
        CMD_READ_SYSTEM_PARAM = "10"
        CMD_READ_DEVICE_PARAM = "20"
        CMD_SET_DEVICE_PARAM = "21"
        CMD_DEFAULT_DEVICE_PARAM = "22"
        CMD_READ_DEVICE_ONEPARAM = "23"
        CMD_SET_DEVICE_ONEPARAM = "24"
        CMD_READ_DEVICENET_PARAM = "26"
        CMD_SET_DEVICENET_PARAM = "27"
        CMD_DEFAULT_DEVICENET_PARAM = "28"
        CMD_READ_DEVICE_TIME = "2B"
        CMD_SET_DEVICE_TIME = "2C"
        CMD_READ_DEVICE_SPECIAL_PARAM = "2E"
        CMD_SET_DEVICE_SPECIAL_PARAM = "2F"
        CMD_READ_FREQ = "3E"
        CMD_SET_FREQ = "3F"
        CMD_STOP_READ = "40"
        CMD_START_READ = "41"
        CMD_ACTIVE_DATA = "45"
        CMD_CHECK_MODULE = "E0"
        CMD_CHECK_ANT = "E1"
        CMD_CLOSE_RELAY = "85"
        CMD_CLOSE_RELAY = "86"
        CMD_HEARTBEAT_PACK = "FF"
        CMD_INVENTORY_TAG = "01"
        COM_READ_TAG_DATA = "02"
        COM_WRITE_TAG_DATA = "03"
  

```
Frame format to send / query data to Reader :



| START = 5357 | length = XXXX | Adr = FF | CMD = from above | DATA = if any | CRC = as per Algorithm |

  


For example We just want to read system parameter then g=frame would be

START = 5357 ,length = 0003,Adr = FF,CMD = 10


```
CRC = 44[ (53+57+00+03+FF+10) =1BC = NOT(1BC) = (E43) => E43+1 = E44 => last 2digit = 44
```
SO complete frame = 53570003FF1044