Power Sensor Remote Operation 1
U2000 Series Programming Guide 39
How to Use Register
There is a method to access the information in status groups:
•the polling method
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
the complexity of setting an SRQ handler.
The Condition Polling Method
In this polling method, the power sensor has a passive role. It only informs the
controller that conditions have changed when the controller asks. 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 that 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. 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.
Status Registers
The Status System in the power sensor is shown in Figure 1- 8. The Operation
Status and Questionable Status groups are 16 bits wide, while the Status Byte
and Standard Event groups are 8 bits wide. In all 16- bit groups, the most
significant bit (bit 15) is not used and is always set to 0.
To Next Page
Loading...
Need help?
General
