1、Much interference between reading and writing

When two or more than two read/write device work at the same time, in order to make the adjacent to read and write without interfering with each other, read and write device during installation to ensure that meet the following two requirements:
1) of two adjacent to read and write the center distance between antennas is greater than 3 m;
2) believe two frequency point of reading and writing, respectively is set to 920 MHZ to 925 MHZ of frequency hopping, fh interval advice 1 MHZ.

2、Initialize the serial port

Serial port resources have been occupied, (including the initialization non-normal exit after a serial port and did not close the serial port, and then to initialize serial port).The computer and read/write device communications baud rate do not agree with reading and writing is the default baud rate;Computer communication serial port to read and write and to read and write the default serial inconsistent;Equipment connection is not correct, contact is not normal

3、The DES algorithm to add and subtract

In VB and part of the data in the use of DES encryption algorithm after reducing mill is different to the original, the solution for: cipher can be defined as a global variable, directly to decrypt decrypt function;Or will the encrypted cryptograph expressed as a BYTE, pass in the address mode

4、why there is no proximity reaction？

Might be the frequency of the card reader and do not match.Please consult the terminal customers to use the card reader how often (how much tolerance), control the frequency of our products, whether card reader frequency does not match with your company.