Test 2-7: Frequency Accuracy (cont’d)
Test Procedure
(cont’d)
3. Set reference oscillator to INT1 or INT2, as specifie d in Table 2-7:
ROSC:SOUR INT1 Set ref osc to INT1
or
ROSC:SOUR INT2 Set ref osc to INT2
4. Set marker source to "ROSC" or "TRIG", as specified in Table 2-7:
MARK:FEED "ROSC"
or Set marker source to
"ROSC"
MARK:FEED "TRIG" Set marker source to
"TRIG"
5. If the marker source is "TRI G", use the following commands to
output a squarewave (otherwise, skip this step):
FUNC SQU; Select squarewave
:FREQ2 <frequency>;Set AFG frequency
:TRIG:SOUR INT2 Set trig source
INIT:IMM Initiate
where <frequency> is the value given i n the "Squarewave
Frequency" c olumn of Table 2-7.
NOTE If the marker source is "TRIG", the marker output frequency will be four
times the frequency of the squarewave, since it takes four points to produce
a squarewave. See Table 2-7 for the expected frequenc ie s.
6. Measure frequency with the Co unter and record the reading in Table
2-11.
Agilent E1445A Service Manual Verification Tests 57