
OPERATION
AND
APPLICATION
UNILINK HOST
ADAPTER 2–42
USER MANUAL
2.10.6 Enabling
and Disabling Macr
os
The ENABLE/DISABLE MACRO EXECUTION command explicitly enables
and/or
disables defined macros for execution. When this command is processed
the
exception flag will
be cleared and the MRSW reset to 0000 hex if the macro is
being enabled, or the MRSW set to the disabled Termination Code 8001 hex if
the
macro is being disabled. Macros will only be enabled when their associated
secondary
device is online, otherwise, the ERROR RESPONSE will be returned
for
that macro.
The adapter will return the ENABLE/DISABLE MACRO EXECUTION
command
code,
the Source Identification number
, and a list containing a pair of
bytes for each requested buffer number. The first byte in the pair is the
requested buffer number and the second byte is the response code which
indicates
whether the requested action was successful.
2.10.7
Initializing the Macr
o Response Buf
fer
There are two ways to insure that only a valid exception will set
the
exception
flag.
The first way was shown in the DEFINE MACRO command. By setting Bit
3 in the macro options byte, the first macro response will be received, but not
compared to the contents in the macro response buffer. Thereafter, the new
responses
will be compared to that first response.
The second way is to store a predefined value in the macro response buffer by
using the INITIALIZE MACRO RESPONSE BUFFER command. A useful
application is to define a macro that retrieves the status information from a
secondary
device and sets the exception whenever the response is not “OK”. The
operating manual for the secondary device gives the exact Primitive response
that should be returned for a status “OK”. Preload this value into the macro
response buffer. Then, the exception flag will be set when the response is
anything
other than the “OK” status that was expected.
The
INITIALIZE MACRO RESPONSE BUFFER command
byte string includes
the Source Identification number, the buffer number, the Primitive response
being preloaded, and an automatic enable byte. The macro must be disabled
before sending this command. The automatic enable byte can then be used to
enable the macro for execution after the response buffer is loaded without
having to issue a separate ENABLE/DISABLE MACRO EXECUTION
command.