Dear All,
AOA

I am trying to send the data from PC, MCU, And MCU to echo same data
But MCU is sending the data to PC, But when I send the command from PC to MCU, It Wont works....

About Code:
After starting MCU is sending 'L', And whatever PC send to MCU, I will ECHO. 4800 baud are being use by PC program. With No hand-shaking, I am using MSCOMM Control. Plz help to resolve the issue.

Hardware connections are:

PC              Max232             MICROCONTROLLER 
P5(gnd)   -->     Pin 15 of Max232 ---> common gnd On MCU
pin 2(Rx) -->  pin 14 of MAX232 --->
               pin 11 of MAX232 --->   pin 11(txd)
Pin 3 txd -->  pin 13 of Max232
               pin 12 of MAX232--->   Pin 10 (rxd)

All capacitor for MAX232CPE IS 1UF 50V

ORG 0
			LJMP MAIN
			
			ORG 23H
			LJMP SERIAL
			
ORG 30H

MAIN:		MOV P1,#0FFH
			MOV TMOD,#20H
			MOV TH1,#0FAH
			MOV SCON,#50H
			MOV IE,#10010000B
			SETB TR1
			MOV R0,#'L'

BACK:		
			CPL P1.2
			MOV A,R0
			MOV SBUF,A
			JNB TI,$

AGN:		INC	R3
			ACALL DELAY
			ACALL DELAY
			ACALL DELAY 
			ACALL DELAY
			CJNE R3,#0FH,AGN
			
			MOV R3,#00H
			SJMP BACK
			
			
;;;;;;;;;;;
SERIAL:		
			
			JNB RI,TRANS
			MOV A,SBUF
			MOV R0,A
			CLR RI
			RETI	
			
			
TRANS:		CLR TI
			RETI


;;;;;;DELAY
DELAY:		MOV R1,#00H
AGAIN:		INC R1
			CJNE R1,#0FFH,AGAIN
			RET

			
END