User's Manual

HF-A21-SMT Embedded WiFi Module User Manual

Shanghai High-Flying Electronics Technology Co., Ltd

www.hi-flying.com

configuration mode through AT+instruction, detailed switch operation refer to “AT+ instruction set”

chapter.

1.4.3. Multi-TCP Link Connection

When HF-A21-SMT module configured as TCP Server, it supports Multi-TCP link connection, and

maximum 32 TCP clients permit to connect to HF-A21-SMT module. User can realize multi-TCP

link connection at each work mode.

Multi-TCP link connection will work as following structure:

Upstream: All dates from different TCP connection or client will be transmitted to the serial port as

a sequence.

Downstream: All data from serial port (user) will be duplicate and broadcast to every TCP

connection or client.

Detailed multi-TCP link data transmition structure as following figure:

Figure 13. Multi-TCP Link Data Transmition Structure

1.4.4. TCPB Function

HF-A21-SMT support 2xTCP function, which means module can support 2 network connections

at the same time. The 2

net work connection called TCPB. TCPB only works as TCP Client and

its configuration can only through AT commanrd, not Web configuration supported. The command

as following,

 AT+TCPB=on, Enable TCPB function;

 AT+TCPPTB=<port>, Set TCPB port number;

 AT+TCPADDB=<IP or domain>, Set TCPB‟s server address;

 AT+TCPTOB=<time>, Set TCPB timeout;

 AT+TCPLKB, Query TCPB link status;

Detailed command describtion refer ro AT instruction chapter. After enable TCPB function, two

network interfaces‟ work mode like “Multi-TCP Link”, All dates from each TCP connection will be

transmitted to the serial port as a sequence and all data from serial port (user) will be duplicate

and broadcast to each TCP connection.

1.4.5. Palmodic Signal

Base on selected factory default setting, nReady signal can have two output statuses:

 Status One: The module will output “0” after normal boot up. This signal used to judge if

module finish boot up and ready for application.

 Status Two: The module will output “Palmodic Signal” after normal boot up.The

palmodic signal is 0.5Hz square wave with dutyfactor 1:1. User can query this signal to

judge if moduleis active “live” or need to re-boot. When module switches to command

mode, it will output “0”, which used to distinguish work mode and command mode.

Notes: