How to avoid DLE getting appended prior to ETX by default


#1

Hi,
When i am transfering the data thru GPRS i am getting DLE character appended prior to ETX character but i dont want it to happen as at my receiving end the data checksum is mismatching.Please tell me how to avoid it to be appended ETX by default.

Thank you in advance
Chethu


#2

Maybe this indicates a flaw in your checksum algorithm?


#3

The data which is to be sent is of the following format

(STX) (ETX)(CRC)… here the CRC is calculated for (STX) + + (ETX) at the transmitting end. But at the receiving end the data will be (STX) (ETX + DLE)(CRC), and on calulation of the CRC it will give error due to extra character DLE appended to data. Please provide solution for this.

Thanking you
Chethu


#4

Ohh I was using the command “AT + WIPDATA =2,1,1” to connect to server, in this case the DLE will be attached to ETX & DLE by default. To avoid this I have to use “AT + WIPDATA=2,1,2” and in this case the DLE & ETX are treated as normal characters.