User's Guide

Guia de usuário Edge-30R+ Autoid / Edge-30R-N+ Autoid

Rev. 13

59 de 92

Messages and replies must contain the prefix "$" (dollar sign followed by space) and the carriage return

terminator <CR>

The "SET" and "GET" functions should be just after the prefix and before the command separated by a

space character.

In the "SET" function, the command should be followed without space of the character "=" (equal)

followed by the value of the parameter you want to change.

Messages sent to the reader may have upper and/or lower case letters.

The TCP connection to the configuration port has a 3-minute inactivity timeout, in which case after an

established connection no data exchange occurs between the Host and the Reader for more than three

minutes, the reader terminates the connection and the Host must reconnect with the Reader.

10.3.3 Checksum of messages

In ASCII message exchanges, you can use two checksum digits at the end of the message and before

the terminator as a way of verifying the integrity of messages exchanged between the host and the

reader. Checksum can be enabled to be used in messages that are transmitted and received from the

reader. The checksum must be calculated and returned as two ASCII characters representing the

hexadecimal value of the module of the sum of the ASCII codes of the message characters, without the

prefix and terminator. Example, message "GET RDPOWER":

$ GET RDPOWER23<CR>

Host → Reader - Host sends message with checksum.

$ 2700C9<CR>

Host ← Reader - Reader responds with parameter value and checksum.

In this example, the sum of the message characters is 0x0323, the checksum of the message should be

the least significant characters of the sum, in this case it is 23.

To disable checksum usage, use the message below:

$ SET CHKSUM=OFFEF<CR>

Host → Reader - Host sends the message with checksum.

When checksum is enabled, the reader response will also contain the two ASCII characters

representing the sum in case a checksum error is detected in a message received by the reader, the

error message "CKERR" is sent to the host. Example, with checksum enabled:

$ GET RDPOWER<CR>

Host → Reader - Host sends message without checksum.

$ CKERR<CR>

Host ← Reader - Reader responds with checksum error.