Model 2110 5½ Digit Multimeter Reference Manual
Appendix B: Status model
2110-901-01 Rev. C/August 2013
B-7
Knowing when a command sequence is finished
Use the following commands to find out when a command sequence has finished.
1. Send a DCL general bus command to clear the Output Buffer and bus controller.
2. Send a *CLS command to clear all bits in the Event Register.
3. Send a *ESE 1 command to instruct the instrument to set the ESB bit in the Status Byte when the
OPC event in the ESR is set.
4. Send the *OPC command to set the Operation Complete (OPC) bit in the Standard Event
Register after all pending commands have been executed.
5. Configure the instrument to generate an SRQ when the ESB bit is set.
SPE, SPD (serial polling)
The SPE, SPD General Bus Command sequence is used to serial poll the instrument. Serial polling
obtains the serial poll byte (status byte). Typically, serial polling is used by the controller to determine
which of several instruments has requested service with the SRQ line.
Read the Status Byte by using *STB?
Reading the status byte with the *STB? command is similar to a IEEE-488 serial poll. However, the
*STB? command:
•
Does not clear the RQS bit (B6) in the Status Byte Register.
•
Is processed like an ordinary command and completes only after previous commands have
completed making it impossible to poll.
Status byte and service request commands
The commands to program and read the Status Byte Register and Status Byte Enable Register are
listed in the following table. For details on programming and reading registers, see Programming
enable registers.
To reset the bits of the Status Byte Enable Register to 0, use 0 as the parameter value for the *SRE
command (for example, *SRE 0).
*CLS and STATus:PRESet commands have no effect on the Status Byte Enable Register.
Status Byte and Status Byte Enable Register commands
Command
Description
*SRE 0
Reset the Status Byte Enable Register.
*SRE <NRf>
Program the Status Byte Enable Register:
<NRf> = 0 to 255 decimal format.
*SRE?
Read the Status Byte Enable Register.