Crestron
e-control Mail SW-MAIL
63
••
Appendices
Installation & Reference Guide — Doc. 5798
to the control system. All the symbols’
rx$
and
tx$
streams are tied to the same
serial driver symbol. The set of signals intended for a particular
Intersystem
Communications
symbol are distinguished from the other sets by their
offset
and/or
their
channel number.
Normally, the signals in an
Intersystem Communication
symbol’s input list and its
output list are internally enumerated starting at the top of each list with zero (0). The
next signal down the input list and the next down the output list are numbered 1; the
next pair, 2; and so forth. These “signal numbers” are transmitted along with the data
and are used at the receiving end to determine what to do with the data.
N
OTE
:
The signal numbers under discussion here are for communications purposes only and are not
utilized in any way outside the
Intersystem Communications
symbol context. The numbering
scheme displayed on the Intersystem Communication symbols in SIMPL Windows has nothing to do
with the actual signal numbering.
Additional
Intersystem Communications
symbols using the same connection must
specify a value to offset their signal numbers by a constant amount. The top signals
in such an
Intersystem Communications
symbol do not begin with zero, but rather
with the supplied offset. This offset must be specified on both sides of the
connection, as follows.
On the server side, the offset is entered into the textbox in the upper right corner of
the signal block definition window. Note in the figure below that the textbox in
question is not labeled
Offset
as one might expect, but
Signals
. The adjacent box
labeled
to
shows the signal number of the last signal in the input or output lists
(whichever is higher). This information helps to determine the offset of the next
signal block.
The
Signal Block Interface
frame from a typical signal block definition window, showing the signal
block’s COM Settings, Vcom channel assignment, and signal offset.
N
OTE
:
In the above example,
Vcom channel
is dimmed because “
SYS
”
specifies a serial connection.
(Only TCP/IP connections have channels.)
On the control system side, in SIMPL Windows the offset is entered into the
offset
textbox at the bottom of the
Intersystem Communications
symbol.
A portion of an
Intersystem Communications
symbol.
showing the
Offset
and
Option
textboxes.
N
OTES
:
