Tektronix 2212 User Manual page 174

General Product Description
B-6
One waveform set (CH 1 and CH 2), 4k record length each, can be
stored in the reference memory as a refernce waveform, giving a
total Bk record length. Previous stored data in the reference
memory is overwritten. A reference waveform may be recalled for
display and comparison with the current acquisition waveform.
The storage system has two acquisition modes, selected by the
SEC/DIV switch setting:
- RECORD
mode. The SEC/DIV must be set to 0.2 SEC/DIV or
faster. A full record is acquired before the acquired data is dis-
played on the crt screen. All triggering modes are selectable.
- ROLL
mode. The SEC/DIV must be set to 0.1 SEC/DIV or
slower. Every new acquired data point is displayed immedi-
ately to the right side of the crt screen and the complete dis-
play is shifted one position to the left. Triggering is disabled,
except in SGL SWEEP (single sweep) mode. "ROLL" is dis-
played in the crt readout.
With the 2212 in X-Y Store mode, the SEC/DIV and /or the EXT
CLOCK INPUT determine the sample rate. The External Clock
Input (EXT CLK )provides input for external clock signals to the
storage circuit when the SEC/DIV switch is in one of the two EXT
CLK positions (RECORD or ROLL).
Appendix B: Specification