Wismo228 - some problems in gprs exchanging mode

[a_gulida]

Hello, All.

i’m started to develop a modem Wismo 228 recently. Use GPRS mode.

After switching to Continuous Transparent Mode with the command at + wipdata = 2,1,2 I am testing the transfer of bytes from 0x00 to 0xff.

As a result discovered the following problems:

1. When send byte 0x0D modem automatically adds the byte 0x0A
   send: 0x0D -> receive: 0x0D 0x0A

2. When send byte 0x0F modem automatically duplicates the transmission
   send: 0x0F -> receive: 0x0F 0x0F

3. If in the course of time more than 2 minutes there wasn’t an exchange then after the resumption of the transfer the first byte coming incorrect into the modem.

Has anyone come across these problems and how to solve them?

Best regards, ANDRIC

[awneil]

@a_gulida

1. When send byte 0x0D modem automatically adds the byte 0x0A
   send: 0x0D → receive: 0x0D 0x0A

Are you sure that is actually added by the modem, and not by whatever receives the data?

[a_gulida]

No, I’m not sure. For testing I used standart Windows HyperTerminal (TCP / IP Server) and Docklight - Serial Com port program for connect to the wismo228 kit.

Perhaps the first two problems are related to the settings of used programs, because when I use Hercules SETUP utility instead HyperTerminal for testing then received bytes are fully from 0x00 to 0xFF the same as sent bytes.