MR8740T_user_manual_eng_20191016H.pdf - 第223页

218 External Sampling (EXT .SMPL)

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217
External Sampling (EXT.SMPL)
12.2 External Sampling (EXT.SMPL)
Externally inputting the signal can control the sampling rate.
How to an input signal
1
Connect each of the EXT.SMPL and GND terminals to an external signal-outputting device
with wires.
2
> [Status] > [Condition]
3
Click the [External sampling] button to set it to [On].
4
Click the box to the right of the [External sampling] box, and then from the list, choose
which direction to use for reception of the external sampling signal.
With the rising edge setting: [
]
With the rising edge setting: [
]
5
Input pulse waves or rectangular waves to the EXT.SMPL terminal. The signal shall have a
high-level voltage of between 2.5 V and 10 V and a low-level voltage of between 0 V and 0.8 V.
Available voltage
range
High level: 2.5 V to 10 V; low level: 0 V to 0.8 V
Pulse width High and low level: 50 ns or more
Response frequency 10 MHz or less
Maximum input
voltage
10 V DC
EXT. SMPL 600 Ω
10 pF
5 V
GND
3 kΩ
5 V
t
t
H
t
L
t
H
> 50 ns, t
L
> 50 ns, t > 100 ns
High
2.5 V to 10 V
Low
0 V to 0.8 V
• If a sampling signal with 5 MHz or more is inputted, trigger points are delayed by one sample.
• When Model 8968 High Resolution Unit is used, the anti-aliasing lter (
> [Channel] > [each Unit] >
[A.A.F.]) setting of [On] is invalid.
12
Externally Controlling the Instrument
218
External Sampling (EXT.SMPL)
219
13 Appendix
13
Appendix
13.1 Information for Reference Purposes
Waveform le size (values for reference purposes)
Waveform le size (for reference)
(MEM le size) = (Setting part size) + (Data part size)
(Setting part size) = 791040 + 512 × [(Number of analog channels) + 4 × (Number of logic channels) +
(Number of real-time calculation channels)]
(Data part size) = {2 × [(Number of analog channels other than Model MR8990 or U8991) + (Number of
logic modules)] + 4 × [(Number of channels of Models MR8990 and U8991) + (Number of
real-time calculation channels)]} × (Number of data sets)
Recording
length
(Points)
Number of channels saved
4 8 16 32 54 108
2.5 k 815 KB 839 KB 887 KB 983 KB 1.1 MB 1.4 MB
5 k 835 KB 879 KB 967 KB 1.1 MB 1.4 M 2.0 MB
10 k 875 KB 959 KB 1.1 MB 1.5 MB 2.0 MB 3.0 MB
20 k 955 KB 1.1 MB 1.4 MB 2.1 MB 3.0 MB 5.2 MB
50 k 1.2 MB 1.6 MB 2.4 MB 4.0 MB 6.2 MB 11.7 MB
100 k 1.6 MB 2.4 MB 4.0 MB 7.2 MB 11.6 MB 22.5 MB
200 k 2.4 MB 4.0 MB 7.2 MB 13.6 MB 22.4 MB 44.1 MB
500 k 4.8 MB 8.8 MB 16.8 MB 32.8 MB 54.8 MB 108.9 MB
1 M 8.8 MB 16.8 MB 32.8 MB 64.8 MB 108.8 MB 216.9 MB
2 M 16.8 MB 32.8 MB 64.8 MB 128.8 MB 216.8 MB 432.9 MB
5 M 40.8 MB 80.8 MB 160.8 MB 320.8 MB 540.8 MB 1.1 GB
10 M 80.8 MB 160.8 MB 320.8 MB 640.8 MB 1.1 GB –
• These sizes, which can be used only as a reference, of text les are acquired when analog channels (other
than Model MR8990 or Model U8991) are used. Any number of logic channels on one module occupies one
channel; one analog channel (Model MR8990 and Model U8991) occupies two channels each.
• The instrument divides les with a size that exceeds 512 MB into multiple les of about 512 MB each to save
them.
13
Appendix