8-20 HP IBASIC Supplement
Interfacing with External Devices
The IBASIC GPIB Model
IBASIC as a Non-Active Controller
The IBASIC program is always the active controller on the internal
interface. There are two cases where an IBASIC program does not have
control of the external GPIB interface:
1. When the host instrument is set as Talker/Listener and active control
has not been passed from an external device.
2. When the host instrument is set as System Controller and the
program has passed control to either the analyzer or another device
on the external interface.
In both of these cases, the program cannot perform activities of any kind
on the external interface.
NOTE An IBASIC program cannot act as a device on the external bus. To
communicate with an external controller, the IBASIC program must be
active controller and the external controller must act as the device (see
“Interfacing with an External Controller” on page 8-21).