Siemens SIMATIC TIWAY 1 - Manual (Page 47)

OPERATION AND APPLICATION
UNILINK HOST ADAPTER 2–37
USER MANUAL
If this command is accepted, the UNILINK Host Adapter will echo back this
same command string, otherwise the ERROR RESPONSE will be returned.
Source Ids can also be used to group network responses, such as the status of
each device. Only one Source Identification number is allocated with each
command sent to the UNILINK Host Adapter.
WARNING
All existing macro buffers for the Source
Identification number will be cleared when the
ALLOCATE SOURCE ID command is
processed. This prevents a task that
abnormally terminated from allocating
additional resources while the original
resources remain allocated, but unused. Make
sure that your application programs use
unique Source Identification numbers.
2.10.4.2 Allocate The Macro Buffers
Use the ALLOCATE MACRO STORAGE BUFFERS command, code 13, to
define and specify the length for both the macro command buffer and the macro
response buffer. The UNILINK Host Adapter will return the buffer number
assigned by the HIU. Store the buffer number in your application program for
later reference. If you specify more than one buffer pair in the command, more
than one buffer number will be returned in the response. Be sure to allocate a
sufficient length of memory for both the macro command buffer and the macro
response buffer.