Keithley 2651A, Справочное руководство

Страница: 772 / 800

Appendix E: Status model Model 2651A High Power System SourceMeter® Instrument Reference Manual
E-14 2651A-901-01 Rev. A / March 2011
Reading registers
Any register in the status structure can be read either by sending the common command query
(where applicable), or by including the script command for that register in either the
print
() or
print(tostring())
command. The
print()
command outputs a numeric value; the
print(tostring())
command outputs the string equivalent. For example, any of the following
commands requests the Service Request Enable Register value:
*SRE?
print(tostring(status.request_enable))
print(status.request_enable)
The response message will be a decimal value that indicates which bits in the register are set. That
value can be converted to its binary equivalent using the information in
Programming enable and
transition registers (on page E-13). For example, for a decimal value of 37 (binary value of 100101),
bits B5, B2, and B0 are set.
Status byte and service request (SRQ)
Two 8-bit registers control service requests: The Status Byte Register and the Service Request
Enable Register. The
Status Byte Register (on page E-14) topic describes the structure of these
registers.
Status Byte Register
The summary messages from the status registers and queues are used to set or clear the appropriate
bits (B0, B1, B2, B3, B4, B5, and B7) of the Status Byte Register. These summary bits do not latch,
and their states (0 or 1) are dependent upon the summary messages (0 or 1). For example, if the
Standard Event Register is read, its register will clear. As a result, its summary message will reset to
0, which will then reset the ESB bit in the Status Byte Register.