Installation Instructions

SIM5216A _HD_V1.02 Hardware Design

SIM5216A _HD_V1.02 26.08.2010

Figure 13: Null modem mode of serial ports

If serial port is used in Null Modem, the pin “RI” can be used as an interrupt pin. Normally it

will stay high but in certain condition such as SMS receiving, incoming voice (CSD, video) call or

URC reported, the pin “RI” will be set low to inform the master, and it will stay low until the

master clear this interrupt with AT command (AT+CRIRS). If using seven lines to setup

communication between devices, the pin “RI” is different. First it stays high, when a voice (CSD)

call coming, the pin “RI” is set to low for about 5900ms, then it is set high again about 100ms.

The situation will repeat until that the call is answered or hung up. After the call is answered or

hung up, the pin “RI” is set high.

Functions of serial port supporting on SIM5216A are as following:

z Standard/Null Modem mode on Serial Port Interface.

z Contains Data lines TXD and RXD, State line RTS and CTS

z Serial Port can be used for CSD, PS service and send AT command for controlling module.

z Serial Port is a high-speed port. It supports the communication rate as following:

300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600,

3200000, 3686400, 4000000

Default band rate is 115200bps. And Data bits=8, Parity=None, Stop bits=1, Flow

control=None.

NOTE:

1 If you need to use a speed higher than 115200, you should consider the length of RS232

line and the speed support on your RS232 port.

2 Though the connector has seven lines for serial port, but the line: DCD, DTR are not

implemented and reserved for future use.

3 The line RI behaves the same as the standard when using four-line mode, but in two-line

mode its action is not standard which is depicted above.