From the manual
' Wait until the character “A” is received serially on Pin1 and put next character into B0
SERIN2 1,16780,[wait (“A”),B0]

' Skip 2 chars and grab a 4 digit decimal number
SERIN2 PORTA.1,84,[skip 2,dec4 B0]

SERIN2 PORTA.1\PORTA.0,84,100,tlabel,[wait (“x”, b0), str ar]