<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                                                       
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997             DEC-31-1997
<PERIOD-START>                             JAN-01-1997             JAN-01-1997             JAN-01-1997
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                           1,969                   2,764                   1,798
<SECURITIES>                                     7,639                   8,639                   9,622
<RECEIVABLES>                                   10,334                   8,811                  10,838
<ALLOWANCES>                                       415                     419                     416
<INVENTORY>                                      5,556                   6,316                   6,250
<CURRENT-ASSETS>                                27,428                  30,329                  30,427
<PP&E>                                           5,607                   5,956                   5,717
<DEPRECIATION>                                   3,201                   3,410                   3,324
<TOTAL-ASSETS>                                  30,099                  33,159                  33,094
<CURRENT-LIABILITIES>                            3,926                   5,016                   3,826
<BONDS>                                          2,978                   3,143                   2,888
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                        11,844                  11,990                  12,132
<OTHER-SE>                                      11,321                  12,904                  14,211
<TOTAL-LIABILITY-AND-EQUITY>                    30,099                  33,159                  33,094
<SALES>                                          7,301                  15,042                  23,475
<TOTAL-REVENUES>                                 8,259                  16,958                  26,374
<CGS>                                            2,737                   5,639                   8,658
<TOTAL-COSTS>                                    3,600                   7,376                  11,383
<OTHER-EXPENSES>                                 2,573                   5,477                   8,473
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                   0                       0                      85
<INCOME-PRETAX>                                  2,165                   4,291                   6,768
<INCOME-TAX>                                       892                   1,645                   2,618
<INCOME-CONTINUING>                              1,274                   2,646                   4,150
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                     1,274                   2,646                   4,150
<EPS-PRIMARY>                                     0.15                    0.32                    0.50
<EPS-DILUTED>                                     0.15                    0.31                    0.47