Keysight E1406A User Manual and SCPI Programing Guide 47Setting VXI-MXI Configuration Configuring the Keysight E1406A Command ModuleDetermining the Table SizeThe user-defined extender table has a one word header and each of the 12 fieldsis also one word. The amount of RAM allocated with DIAGnostic:NRAM:CREate isspecified in bytes. Since one word is two bytes, the amount of RAM to allocate iscomputed as:2 + 24(N)where N is the number of modules to be configured. For example, to provideinformation for three extender devices, the table size would be:2 + 24(3) = 74 bytesDIAGnostic:NRAM:CREate would be executed as:OUTPUT @E1406;"DIAG:NRAM:CRE 74"Data FormatData can be sent to the extender table in any convenient format, as long as thebinary data is preserved. This can be accomplished using DIAGnostic:PEEK? andDIAGnostic:POKE, by reading the data into a variable in the computer and thendownloading the data to the table using the Arbitrary Block Program Dataformat, and so forth. In the following example, this is accomplished by readingthe data into 16 bit integer variables in the computer and then downloading thedata to the table using the ANSI/IEEE 488.2-1987 Arbitrary Block Program Dataformat. More information on the Arbitrary Block Program format can be found inthis manual and in the ANSI/IEEE 488.2-1987 document.The table header is sent as a single 16-bit word which must contain the ValidFlag and the number of modules involved. For a valid table, the header is 256plus the number of modules. For example, to indicate a valid table with sevenentries, the header is 263 (256 + 7 = 263).When downloading data into the user-defined extender table,DIAGnostic:DOWNload does not determine if the table is largeenough to store the data. If the amount of data sent byDIAGnostic:DOWNload is greater than the table space allocatedby DIAGnostic:NRAM:CREate, system errors will occur. You canrecover from these errors by executing DIAG:BOOT:COLD, or bypressing the "Ctrl-R" keys on an RS-232 terminal while cyclingmainframe power.
