Cards and Proximity
125 kHz Proximity Access Control
125 kHz proximity is the long-serving card and fob technology in older buildings. xSERVA readers read EM4100 and HID Prox, so existing fobs and cards migrate straight onto the new platform.
Frequency 125 kHzStandard Low-frequency RFID (EM4100, HID Prox)Range 0 to 10 cmSecurity Basic
Technical Facts
What You Need to Know
- Frequency
- 125 kHz low-frequency RFID
- Families
- EM4100 and compatible, HID Prox
- Typical use
- Key fobs, clamshell cards, gate and car-park access in older sites
- Security level
- Basic. The card simply sends a fixed number, which can be copied with inexpensive tools
- On xSERVA
- Read by UltraPASS-Door, with the repeat-tap guard and UID encoding options
Strengths and Limits
Where It Fits
Strengths
- Very common and cheap
- Fobs and cards are rugged
- Zero re-badging on migration
Limits
- Fixed number, no encryption
- Easy to clone
- Not suitable alone for sensitive doors
Our Advice
How to Use It Well
Fine for gates, car parks and low-risk doors. Add a PIN, face or phone credential on anything that matters, and replace fobs with DESFire over time.
Other Card Technologies
Questions
125 kHz Proximity Questions
Do my old proximity fobs work with xSERVA?
Yes, in the EM4100 and HID Prox families. The UltraPASS-Door reader reads 125 kHz proximity and 13.56 MHz cards in one unit.
Are 125 kHz cards secure?
They send a fixed number with no encryption, so they can be copied. Use them for low-risk doors, or pair them with a second factor.
Can one reader read both 125 kHz and 13.56 MHz cards?
Yes. The multi-format UltraPASS-Door panel reads both, which lets a site run old and new cards together during a migration.