Agilent Technologies E1300B, E1301B, 75000 SERIES B user manual Using Mainframe Data Memory

Figure 4-4. Synchronizing Internal/External Instruments and Computer

Mainframe Data Memory

Using Mainframe Data Memory

When power is applied or the system rebooted (DIAG:BOOT command), mainframe memory is automatically configured to provide a predefined amount of memory for any installed instruments that require memory space. For example, each multimeter instrument within the mainframe is allocated enough memory to store 100 readings.

Mainframe memory is also automatically re-allocated upon demand while programming. For example, if greater than 100 readings are requested for a multimeter, the mainframe computes the amount of memory required for these extra readings. If enough memory space is available, an additional amount is allocated to the multimeter and the readings are stored. If enough memory is not available, an error message occurs and the command is aborted. The memory allocated to an instrument above the initial power-on amount remains dedicated to that instrument until that instrument is reset (*RST command) or until power is cycled. Once de-allocated, the memory is available to other instruments.

Commands that generate data and do not have a question mark (?) in their syntax store the data in mainframe memory. Faster instrument reading rates are possible when using reading memory versus sending data directly to an external computer. Storing readings in memory can also help to ensure that the period between paced readings is maintained at a constant value. When instrument data is stored in memory, it overwrites any data previously stored by that instrument. You can retrieve data stored in mainframe memory using the FETCh? command.

4-6 Using the Mainframe