User`s manual

190 Chapter 6
O:\Manuals\E6380A_Progguid\Book\Advoper.fm
Advanced Operations
Passing Control
Requesting Control using IBASIC
The Test Set has the capability to request control of the bus from the
Active Controller from a running IBASIC program using the IBASIC
command EXECUTE ("REQUEST_CONTROL"). When the EXECUTE
("REQUEST_CONTROL") command is executed from a running
IBASIC program, the Request Control bit, bit 1, of the Test Set’s
Standard Event Status Register is set to the TRUE, logic 1, condition.
The Active Controller detects the request in the Test Set’s Standard
Event Status Register either as a result of an SRQ indication by the
Test Set or by some polling routine which periodically checks bit 1 of the
Standard Event Status Register of all potential controllers on the bus.
The Active Controller would then send the Test Set the address to
which the Test Set is to later pass control using the *PCB Common
Command. The Active Controller would then pass control to the Test
Set.