Test 2-7: Frequency Accuracy (cont’d)
Test Procedure
(cont’d)
Table 2-7. Frequency Accuracy Test Points
Ref Oscillator
Source Marker
Source Squarewave
Frequency (Hz) Test Limits
(Hz)*
INT1
INT2
INT2
INT2
INT2
"ROSC"
"ROSC"
"TRIG"
"TRIG"
"TRIG"
----------
----------
5.0 E6
3.333 E3
76.294
42.94967 E6 ± 0.005%
40 E6 ± 0.005%
20 E6 ± 0.005%
13.3333 E6 ± 0.005%
305.176 ± 0.005%

*Add aging rate of ±20 ppm/year

Example Program

This program performs the Frequency Accuracy Test.

10! RE-STORE "OSC_FREQ"
20 DIM Freq(1:5)
30 !
40 !---------- Set up I/O path and reset AFG ----------
50 ASSIGN @Afg TO 70910
60 OUTPUT @Afg;"*RST;*CLS" !Reset AFG
70 !
80 !---------- Ini tialize variables ----------
90 DATA 42.94967E6,40E6,20E6,13.3333E6,305.1 76
100 READ Freq(*)
110 !
120 !---------- Set u p C o unter ----------
130 CLEAR SCREEN
140 PRINT "Set up Counter:"
150 PRINT
160 PRINT " Function -- Frequency"
170 PRINT " Input Impedance -- 50 ohms"
180 PRINT
190 PRINT "Connect the Counter to ’Marker Out’ on the E1445A. "
200 PRINT
210 DISP "Press ’Continue’"
220 PAUSE
230 CLEAR SCREEN
240 !
(Continued on next page)
58 Verification Te sts Agilent E1445A Serv ice Manual