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How the compatible Cotag / Bewator / Granta (active+passive) works
The Cotag / Bewator / Granta (active+passive) is a 125 kHz low-frequency proximity credential — the band most legacy prox readers use. Its data structure is Cotag proprietary ASK+Manchester at very low bitrate / very high clock (RF/768); long repeating binary, number stored LSB-first; active (~50 kHz) and passive (125-132 kHz) variants. When you present a credential, the reader decodes that exact structure and passes it to your access-control panel as a card number it recognises.
We build the compatible Cotag / Bewator / Granta (active+passive) by encoding the matching data structure onto a programmable T5577 chip. Once written, the credential presents the same bits, the same facility code, and the same card number your reader already accepts. That is what "compatible by specification" means: not a generic look-alike, but a credential engineered for the exact format your system expects.
To order, tell us the part number or format printed on your existing Cotag card, and our specialists confirm the encoding before anything ships. Bulk and reorder quantities are welcome — pricing is a fraction of OEM list, and every credential is verified to read on your existing equipment.
Also known as
Cotag · Co-tag · Cotag 958 · Cotag passive prox · Cotag active · Bewator · Bewator Cotag · Granta
Cotag and all other brand and product names are trademarks of their respective owners. Security ID Systems is an independent manufacturer and supplier of compatible access-control credentials and is not affiliated with, authorized by, sponsored by, or endorsed by these companies. Brand and format names are used only to identify the systems our products are compatible with.