Control Functions
PSI BOX PLUS+ Reference
TCT.
Sends The Take Control Command.
_____
_______________________________
Purpose.
The addressed command Take Control is sent to the
__________
IEEE bus.
The TCT command is used after a talk address to tell the
device to take control of the IEEE bus.
The PSI BOX asserts ATN and becomes the active
controller, then the IEEE command TCT, hex 04h decimal 4, is
sent over the IEEE bus. After the command has been sent the
ATN remains true, PSI BOX is the active controller. The NO
ATN command should be used to drop the ATN line false so
allowing the addressed controller to assert ATN and become the
active controller.
The TCT command is used automatically in the PASS
routine but it can be called separately to perform your own
transfer control routine. The TCT command can also be sent by
using CMD 9 or CMD 137
Format.
TCT
_________
Params.
None.
_________
Returns.
None.
__________
Example.
________
_
BUS TCT
recommended sequence
BUS UNL TALK 3 TCT NO ATN
Bus Activity.
___________
_
assert ATN if not already so
TCT
recommended sequence.
UNL
TAD 3
TCT
(PSI BOX drops ATN new controller asserts ATN)
Chapter 8
Page 153
