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[Bruce]

If you have control over the PC application, then have it ping the data logger (sending an occasional byte) until the logger responds.

On the PIC side, simply test RCIF on occasion to determine if the PC has been connected, the ping byte has been received, and the RCREG holds something.

The USART can handle all this in the background, and your main code can do whatever until the PC is connected.

Y       VAR byte    ' Inbound data recovered from RCREG
RCIF    VAR PIR1.5  ' USART received character interrupt flag bit
CREN    VAR RCSTA.4 ' USART continuous receive enable bit
OERR    VAR RCSTA.1 ' USART over-run bit

INTCON  = 0      ' Disable interrupts (just using flags)
ADCON1 = 7      ' A/D off

TRISB.0 = 0     ' Set RB0 to output
PORTB.0 = 0     ' LED off (indicates data was in RCREG)
   
Main:
    IF RCIF THEN Have_Data ' If RCIF=1 there's data in RCREG
    HIGH 1          ' so jump to Have_Data and send your EEPROM
    PAUSE 1000      ' contents
    LOW 1
    PAUSE 1000      ' Long pauses show how RCREG receives data
    GOTO Main       ' in the background
        
Have_Data:          ' Send your EEPROM data here
    PORTB.0 = PORTB.0 ^ 1 ' Toggle RB0 to indicate data rcvd
    WHILE RCIF            ' Empty RCREG by reading it
     Y = RCREG
    WEND
    ' If OERR = 1 then the over-run bit is set and we need to clear it
    ' to re-enable receive. If not, then carry on
    IF !OERR THEN  Main  ' If no over-run condition, return to Main
    CREN = 0             ' Over-run condition. Disable receive
    CREN = 1             ' Re-enable & clear OERR flag
    GOTO Main