Greetings,

This may only require a one word answer but I would be very grateful for some advice.

I have a circuit with ten RFID card scanners individually driven by relays controlled by a micro-controller. The scanners are connected in parallel, which I understand reduces the total inductance of the circuit. They are far enough apart not to cause any mutual inductance. I have noticed that when more than one scanner is powered the range at which they can read an RFID tag is greatly reduced.

Can I overcome this problem if I connected the scanners in serial? Or could this merely cause the circuit voltage to drop too low for the scanners to function. If so can anyone offer any advice as to how I can maintain the read range of the scanners whilst being able to use more than one at a time.

Thanks for your time.

Richard

 

Hi fazz!
If you could post the diagram of the circuit, I may be of some help.
It could be power, frequency or coding but hard to tell without diagram.

 

Greetings,

This may only require a one word answer but I would be very grateful for some advice.

I have a circuit with ten RFID card scanners individually driven by relays controlled by a micro-controller. The scanners are connected in parallel, which I understand reduces the total inductance of the circuit. They are far enough apart not to cause any mutual inductance. I have noticed that when more than one scanner is powered the range at which they can read an RFID tag is greatly reduced.

Can I overcome this problem if I connected the scanners in serial? Or could this merely cause the circuit voltage to drop too low for the scanners to function. If so can anyone offer any advice as to how I can maintain the read range of the scanners whilst being able to use more than one at a time.

Thanks for your time.

Richard

The delay in reponse may be due to the fact that RFID tag readers employ an anti-collsion scheme. If the readers can sense an adjacent reader they may be trying to implement the anti-collision method that has the RFID tag and the reader temporarily confused.

hgmjr