Table of Contents
Advertisement
How to use registers
There are two methods to access the information in status groups:
– the polling method, or
– the service request (SRQ) method. (GPIB mode only)
Use the polling method when:
– your language/development environment does not support SRQ interrupts.
– you want to write a simple, single-purpose program, and do not want to add
Use the SRQ method when you:
– need time-critical notification of changes.
– are monitoring more than one device which supports SRQ interrupts.
– need to have the controller do something else while it is waiting.
– cannot afford the performance penalty inherent to polling.
Condition polling method
In this polling method, the N432A has a passive role. It only informs the controller
that conditions have changed when the controller queries. When you monitor a
condition with the polling method, you must:
1 Determine which register contains the bit that monitors the condition.
2 Send the unique query that reads the register.
3 Examine the bit to see if the condition has changed.
The polling method works well if you do not need to know about the changes the
moment they occur. The SRQ method is more effective if you must know
immediately when a condition changes. Detecting an immediate change in a
condition using the polling method requires your program to continuously read
the registers at very short intervals. This is not particularly efficient and there is a
possibility that an event may be missed.
For an example on measurement polling, refer to
Using VEE"
Keysight N432A Programming Guide
the complexity of setting an SRQ handler.
on page 509.
N432A Remote Operation
"Measurement Polling Example
1
99
Advertisement
Table of Contents
