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CHAPTER 5: Command Descriptions
The @ character, referred to as the ID character, can be changed or disabled by using the ID command.
If it is anticipated that the ID character may be part of the data within an OUTPUT or SEND command,
it should be disabled.
SYNTAX
@
RESPONSE
None
MODE
Any
BUS STATES
None
EXAMPLE
PRINT #1,"@"
@@ Command
Sending the system command @@ causes the 488 Controller to return to power-on conditions. All data
buffers are cleared, and any software-programmable terminators are returned to the power-on conditions.
This is the only command which does not require a serial terminator to execute. Reset is executed upon
receipt of the second @.
When the @@ command is received, the serial handshake line (RTS) is unasserted. It is asserted when the
488 Controller can buffer commands. If X-ON/X-OFF handshake is selected, the software handshake state is
reset.
The @ character, referred to as the ID character, can be changed or disabled by using the ID command.
If you anticipate that the ID character may be part of the data within an OUTPUT or SEND command,
it should be disabled.
SYNTAX
@@
RESPONSE
None
MODE
Any
BUS STATES:
IFC,*IFC
(SC)
EXAMPLE:
PRINT #1,"@@"
ABORT Command
As the System Controller (SC), whether the 488 Controller is the Active Controller or not, the ABORT
command causes the Interface Clear (IFC) bus management line to be asserted for at least 500 micro-
seconds. By asserting IFC, the 488 Controller regains bus control even if one of the devices has locked it up
during a data transfer. Asserting IFC also makes the 488 Controller the Active Controller. If a Non-System
Controller was the Active Controller, it will be forced to relinquish control to the 488 Controller. ABORT
forces all IEEE bus device interfaces into a quiescent idle state.
Содержание 488 Controller
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Страница 95: ...93 CHAPTER 9 Theory of Operation Board Layout Figure 9 2 The interface converter s serial I O board...
Страница 102: ...488 CONTROLLER 100 How To Read the Chart Hexadecimal Decimal Equivalent Equivalent ASCII Character Address or Command...