NeXT 125kHz not working

Hello all,

today I get on mydesk NeXT version RFID + NFC.

  • 13.56MHz NTAG216 ISO14443A NFC chip
  • 125kHz Atmel T5577 RFID emulator chip

NFC chip on 13.56MHz work great, but I have problem with 125kHz RFID.

RFID not working with our door access system based od Dahua RFID 125kHz reader (Dahua ASR1200D-D, 125khz, EM cards) also nothing happed on Jablotron Security system (i try change settings to accept different freq. in jablontron configuration).

Is there problem with T5577 emulation modes or something else ?
What is really strange, in implant kit is RFID diagnostic card for 13.56MHz and 125 kHz, after insert this card into em field od 125khz reader nothing happend, i try diffent readers but it’s same.

Please help. thx. FAHA

I try

THAT is very strange

I looked it up, and it states
Additional info * RS485, Wiegand34/26 protocol(Default 34)

  • 13.56MHz(Mifare)
  • 125KHz(EM-ID)

Both frequencies, So your diagnostic card SHOULD have lit up :bulb: , very strange.

Can you scan your genuine card/fob on the system and share the results that show up on Jablotron Security system?
This may help us to figure out the UID, so we can work out how many bits the UID has which may help us work out what chip we are working with. ( change some of the figures for your security )

FYI Your NExT should be by default in EM41xx with a 40 bit UID

Because it is a Dual frequency reader, Just so we can rule HF out, Can you try scanning your card with your phone with TAGInfo App.

When you scanned the Diagnostic card, was it very bright where you scanned it? :sun_with_face:

Did you try scanning the diagnostic card on the reader and then place your access card on top of the diagnostic card, to see if it lit up when access was accepted.

Just in case the diagnostic card is broken, Do you have the Field detectors to try also?

If you can try those for now, and we will see what we can do next

I don’t get why RFID diagnostic card is not working.
(I have 3 pieces of diagnostic card and none of them is working)

In company building all Dahua readers are only 125kHz.

125khz DAHUA reader

I temporary connect one Dahua 13.5Mhz reader and it’s working very well, including diagnostic card.

Hmmmm, I’m pretty confused also.
Let me think on it… whilst I sleep.
Just about 0100 here.
Hopefully before I wake up somebody else has a suggestion or answer for you

I know it seems silly but have you moved the diag card around the entire face of the reader? The 125khz section of the card is the center coil, so it might be a positioning thing?

I also like this idea… some readers can behave oddly with passive coils with no chips attached, though I would not put the access card exactly and directly over the diag card… just near it.

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I know it seems silly but have you moved the diag card around the entire face of the reader? The 125khz section of the card is the center coil, so it might be a positioning thing?

I try moved a lot, many positions, but it’s the same problem.

Did you try scanning the diagnostic card on the reader and then place your access card on top of the diagnostic card, to see if it lit up when access was accepted.

god idea, i try it, but it’s the same problem.

Tomorrow I get from Arduiono shop USB reader RFID 125Khz for EM4100 EM410X cards and try read chip and diagnostic card.

And silly question, is there possible measure mV (voltage) on coil via simple multimeter device or is really oscilloscope needed ?

Not a silly question… maybe v2 should have test pads for this!

nudge nudge wink wink
I got it

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Wow, you managed to get the big guns out to help you; great because I woke up a couple of times through the night and I’m still stumped.

Hello again,

I read this topic -> Quirks of the T5577 & cloning tags to the xEM.

Could be a problem in antenna design ?


In short, it was not the cloner’s code or what it was doing that was the problemthe problem was that the antenna coil inside the cloner was designed to work with cards and keyfobs, not small cylindrical tags like the xEM. The cloner was not magnetically coupling well with the xEM, and because passive RFID systems use this magnetic field to send both power and data over the coupling, there was a significant chance that the T5577 chips inside these xEMs were being corrupted.

?

I will let Amal answer that for you.
That faq also says

" We turned to the defacto standard RFID hacking tool, the Proxmark3 , to see if we could not only diagnose the problem, but also recover / restore any of these “bricked” xEMs. The news there was not good either, but mostly because so many people who attempted to use this expensive diagnostic tool quickly found that its standard “factory” 125kHz antenna was also ill suited to the task of talking to the small, cylindrical xEM tag."

There is now a suitable antenna.
If this is the case, do you have a PM3 RDV4 with an LF antenna?

It would be good to know if the Dahua system has damaged/ corrupted your implant.
That will be a good lesson for the whole community and we should record that.
First we need to find out IF that is the case?

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It may also be worth using a card or key fob form factor t5577 to test.

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Helle again,

today I get on my desk RFID USB reader 125kHz emulates HID device. (keyboard)
Exactly this device:
https://arduino-shop.cz/arduino/954-usb-rfid-ctecka-125khz.html

And guess what ? It’s working! I can read my hand implant correctly. ;-).

But RFID diagnostic card on the same USB reader does not show any activity, that’s weird.
I try 3 different RFID diagnostic cards, but it’s same.
F.

RFID diagnostic card on the USB reader.
LED diode does not indicate presence of elmag. field, but reader is working.

A now big question, why DAHUA readere on same freq. 125kHz is not working ?
Probably problem in antenne design or RF parts ? Or is this software problem ? Can be fix usb the working USB reader ?
Thx F.

Did you try putting it between the reader and a tag? I am also assuming you moved it around.

The DT logo circle is directly overtop of the 125kHz coil in the RDC. To get a better idea of why it might not be picking things up, I suggest carefully taking the case of the reader apart so we can all see the antenna coil inside, then we can make suggestions as to better positioning or why it might not be working at all.

The other issue aside from coupling is power output. The RDC coil uses thick traces and multiple layers to increase current for the LED so a weak output field (low voltage) may not have enough juice to properly light the LED on the card… tape over the red LED of the reader with some black electrical tape and try the RDC in total darkness to see if you can see any glimmer of light from the LF side.