Racal Instruments 3162A/B, User Manual

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User Manual 3162A/B
Using The Instrument 3-34
SMEMory:MODE {READ | WRITe}
sets the instrument to receive (WRITE) data from or send (READ) data to the
VXIbus.
The query:
SMEMory:MODE?
queries the shared memory mode and returns “READ” or “WRITE”.
The command:
SMEMory:STATe {OFF | ON}
places the Model 3162B in the shared memory state when ON is selected.
After this, the instrument cannot accept normal commands. Data must be sent
to the generator using shared memory access. Normal command mode is
resumed when the SMEMory:STATe is changed to OFF.
The query:
SMEMory:STATe?
queries the shared memory state and returns "0" (OFF) or "1" (ON).
The following sequence should be used for shared memory transfers:
1. Slot 0 sends commands:
TRAC:DEF (n),(m) (Shared Memory write only)
TRAC:SEL <n>
SMEM:MODE {READ
*
WRITE}
SMEM:STATE ON
2. Slot 0 repeatedly sends:
*OPC?
When response is 1, shared memory transfers may start.
3. Use an I/O routine such as ViMoveAsync (from the VISA I/O
library) to transfer the data (See previous example).
4. Slot 0 sends command:
SMEM:STATE OFF
once data transfer is complete (the ViMoveAsync command completion
information).
The *OPC? response is set to 1 when the Model 3162B has transferred
memory access from the internal CPU to shared memory. This typically takes
a few milliseconds.