User`s manual

The Command and
Parameter Registers
Commands and their parameters are opcodes written to the Command and
Parameter Registers.
Address 15 - 8 76543210
base + 08
16
Not Used Command Opcode
Address 15 - 8 76543210
base + 0A
16
Not Used Parameter Opcode
Command Structure. Multimeter commands consist of a command
opcode and a parameter opcode (which may be optional). The opcodes
must be in 2’s complement binary format when written to the registers.
An example of how to write to the Command and Parameter Registers is
shown in the following statements. The statements set the multimeter
function (command opcode 4) to DC voltage (parameter opcode 0):
!Write command
iwpoke((unsigned short *)(base_addr_dmm + 0x08),4)
!Write parameter
iwpoke((unsigned short *)(base_addr_dmm + 0x0A),0)
When the command and parameter are received, the multimeter processor
checks for the proper syntax and range. If an error is found, the NOERR bit in
the Status Register is cleared (0), and operation continues (if it is possible).
Note When you are writing (sending) commands and parameters, the multimeter
needs time to process the current command before the next command is sent.
204 HP E1326B/E1411B Multimeter Register-Based Programming Appendix C