<ARTICLE> 5 <MULTIPLIER> 1,000 <CURRENCY> US DOLLARS <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-START> JAN-01-1998 <PERIOD-END> JUN-30-1998 <EXCHANGE-RATE> 1 <CASH> 29,003 <SECURITIES> 129,319 <RECEIVABLES> 29,961 <ALLOWANCES> 705 <INVENTORY> 7,981 <CURRENT-ASSETS> 203,639 <PP&E> 23,114 <DEPRECIATION> 11,585 <TOTAL-ASSETS> 248,002 <CURRENT-LIABILITIES> 28,181 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 409 <OTHER-SE> 215,821 <TOTAL-LIABILITY-AND-EQUITY> 216,230 <SALES> 83,618 <TOTAL-REVENUES> 83,618 <CGS> 20,509 <TOTAL-COSTS> 73,271 <OTHER-EXPENSES> 2,600<F1> <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 0 <INCOME-PRETAX> 23,042 <INCOME-TAX> 9,863 <INCOME-CONTINUING> 13,637 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 13,637 <EPS-PRIMARY> .33 <EPS-DILUTED> .32 <FN> <F1>Other expenses refers to expenses incurred in conjuction with the acquisition and integration of Intrusion Detection Inc. </FN>