N-Ddatastore;Armandsetsize - Keithley 486 Instruction Manual

SECTION4
IEEE-488 Reference
4.2.12
N - Data Store; Arm and Set Size
Purpose
To arm, and set the buffer size of the data store.
Format
Nn
Parameters NO Set data store buffer for wrap around (endless) operation.
Nn Set data store buffer size "II" where "n" = 1 to 512.
Default
Upon power-up, or after receiving a DCL or SDC comman d, the instrument returns to the N
option that was saved as the default condition.
Description
When the N command is sent over the bus, the data store becomes armed and starts storing
readings when the appropriate trigger occurs. The rate that readings are stored is determined
by the Q command (see paragraph 4.2.15).
In the wrap around data storage mode (NO), storage will not stop after the buffer is filled (512
readings), but will proceed back to the first buffer location and start overwriting data. With the
Nn command, the storage process will stop when the defined number of readings have been
stored. In this case, the buffer is considered to be full.
To store readings at a selected interval (Qn), the instrument must be in a multiple trigger mode
WI, T2,
T4,
T6 or TS). When the selected trigger occurs, the storage process will commence.
In a one-shot trigger mode (Tl,T3,T%T7 or T9), the instrument will store one reading each time
the appropriate trigger occur. See paragraph 4.2.18 for details on trigger commands.
Programming
Notes
1. WhentheN
co
mmand is sent, "------*' will be displayeduntil the first trigger occurs.
2. Data storage can be stopped by sending a command that changes the trigger mode or
source CT command), trigger delay iW command), or trigger interval (Q comman d). Data
storage can also be aborted by x-arming the data store (N command).
3. Either during or after the storage process, readings may be recalled by using the Bl, B2,B3
or B4 command. In wrap-around buffer mode, data store must be stopped before readings
may
be taken from the buffer. Attempting to read the buffer while wrap-around data store
is in progress will hang the bus.
4-24