Ametek 7230 Instruction Manual page 100

Chapter 6, COMPUTER OPERATION
NNBUF [n]
TC [n]
TC.
SYNC [n]
6-14
synchronous time constant control is turned off, the fast analog output mode is
turned on (FASTMODE 1), and the output filter slope is set to 12 dB/octave if it had
previously been 18 or 24 dB/octave.
Noise Buffer Length control
The value of n sets the noise buffer length according to the following table:
n Function
0 Noise buffer off
1 1 second noise buffer
2 2 second noise buffer
3 3 second noise buffer
4 4 second noise buffer
Filter time constant control
The value of n sets the output filter time constant in accordance with the following
table:
NOISEMODE
= 0
n time constant
0 10 µs
1 20 µs
2 50 µs
3 100 µs
4 200 µs
5 500 µs
6 1 ms
7 2 ms
8 5 ms
9 10 ms
10 20 ms
11 50 ms
12 100 ms
13 200 ms
14 500 ms
15 1 s
N/A means that n is an illegal value under these conditions.
The TC. command is only used for reading the time constant, and reports the current
setting in seconds. Hence if a TC 12 command were sent and the noise measurement
mode was turned off, TC would report 12 and TC. would report 1.0E-01, i.e. 0.1 s or
100 ms.
Synchronous time constant control
n Effect
0 Synchronous time constant disabled
1 Synchronous time constant enabled
NOISEMODE
= 1
time constant n
N/A 16
N/A 17
N/A 18
N/A 19
N/A 20
500 µs 21
1 ms 22
2 ms 23
5 ms 24
10 ms 25
N/A 26
N/A 27
N/A 28
N/A 29
N/A 30
N/A
NOISEMODE NOISEMODE
= 0 = 1
time constant time constant
2 s N/A
5 s N/A
10 s N/A
20 s N/A
50 s N/A
100 s N/A
200 s N/A
500 s N/A
1 ks N/A
2 ks N/A
5 ks N/A
10 ks N/A
20 ks N/A
50 ks N/A
100 ks N/A