Unitech MR350MKII manual Open RS-485 multi-bus to send out data

default: cc=0x70; break;

}

switch (parity)

{

case 0 : break;

case 1 : cc=cc0x04; break;

case 2 : cc=cc0x0c; break;

case 3 : cc=cc0x08; break;

}

switch (stop)

{

case 1 : break;

case 2 : cc=cc0x02; break;

}

switch (data)

{

case 7 : break;

case 8 : cc=cc0x01; break;

}

TD_int_dos1(0x1C,cc,1,0); regs.h.ah = 0; regs.h.al = cc; int86(0x33,®s,®s);

}

05Open RS-485 multi-bus to send out data

The RS-485 is a multi-bus architecture that means more than one RS-485 I/O port can access the trunk line. Thus, if the RS-485 intends to do serial data input/output, it must occupy the bus first to prevent from other linked terminals to send or receive data. The bus will be released while the data transmission is done and then release the bus to be used by other terminals for data transmission.

Entry Parameters:	AH = 5
Returned Values:	None

void TC_485_open()

{

regs.h.ah = 5; int86(0x33,®s,®s);

}

3-32