Siemens SIMATIC TIWAY 1 Manual De Usuario

The LINK MACRO command links two macros together to form an
“unconditional store and forward” command sequence that enables host
initiated secondary-to-secondary communications. The first macro reads data
from a secondary device and stores it in the second macro buffer. It then triggers
the second macro to write the response to another secondary. The two macros
are referred to as the trigger macro and the action macro respectively.

As long as a link exists between the two macros, the action macro is only
executed when the trigger macro is enabled and has triggered the action macro.
Disabling the trigger macro automatically disables the action macro even if the
action macro has started execution. If the action macro has been queued for
execution before it is disabled, it will complete execution, but the response will
be dropped.

1C ss b1 b2 oo (vvvv...)

1C ss b1 b2

OPERATION

MHIU, HIU

ss

The common Source Id. The linked macros must have the same
Source Id.

b1

The trigger macro buffer number.

b2

The action macro buffer number.

oo

The option number.

vvvv

The option parameter. This field will be used for future
enhancements.

The following describes the options and their associated
parameter values.

Option–00 = Terminate link. This option terminates the link between the

macros specified in the b1 and b2 fields.The trigger macro must
be disabled before the link can be terminated.

Option–01 = Unconditional Store and Forward (USF). This special link

requires a trigger macro using Primitive 20 or A0 to read the data
from a secondary and an action macro using Primitive 30 or B0 to
write the data read to  another secondary.

Each time the trigger macro completes a read, it is disabled and
its data is moved into the action macro buffer to create a valid
write Primitive and the action macro is enabled. If the trigger
macro receives an error from the secondary, the exception flag