User Manual

14.2 External I/O
395
14
Chapter 14 External Control
2 In the Status Settings screen (Memory Function), make the following external
sampling settings.
3 Input HIGH level (3.0 to 5.0 V) and LOW level (0 to 0.8 V) pulse waves or rectan-
gular waves to the EXT.SMPL terminal.
Data is sampled on the rising edge, falling edge, or both edges of the input
waveform. Note that the sampling frequency is limited by the selected edge or
edges. ("Supported external sampling pulse widths" (⇒ p. 394))
↑ Sample on rising edge.
↓ Sample on falling edge (default setting).
↑&↓ Sample on both rising and falling edges.
(To open the screen: Press the SET key → Select with the SUB MENU key→
Status Settings screen)
Set Sampling clock to [EXT].
Set the number of data points to display pe
r
division on the horizontal axis (time axis).
Input range: 10 to 1000 (Default setting
:
100)
See "Entering Numbers" (
⇒ p. 64)
Select the input waveform sampling meth
-
od. (This can also be set in the Ext Term
Settings Screen.
• When a sampling signal of 5 MHz or greater is input, trigger points are
delayed by 1 sample.
• It is recommended that the Roll Mode function be set to [On] when the exter-
nal sampling input signal is 100 kHz or lower (⇒ p. 99). When the Roll Mode
function is set to [Off] or [Auto], external sampling data is collected and saved
in memory after external sampling signals (rising, falling, and both rising and
falling) are input 32 times.
When the 8958 16-Ch Scanner Unit is installed
• Input sampling input signals of 100 kHz or lower. Signals higher than 100 kHz
cannot be sampled.
• During scanning, if they overlap with the external sampling frequency, chan-
nels where scanning is finished exist at the same time as channels where
scanning is not finished. Data may be sampled according to the timing shown
in the figure below.
CH1 Dn-1
EXT.SMPL
8958
CH1
CH2
CH3
CH4
CH5
CH6
CH7
CH8
CH1 Dn
CH2 Dn-1 CH2 Dn
CH3 Dn-1 CH3 Dn
CH4 Dn-1 CH4 Dn
CH5 Dn-1 CH5 Dn
CH6 Dn-1 CH6 Dn
CH7 Dn-1 CH7 Dn
CH8 Dn-1 CH8 Dn
Scanning operation
Scanning operation
Scanning operation
Sampled data
External sampling timing