Crestron
e-control Mail SW-MAIL
66
••
Appendices
Installation & Reference Guide — Doc. 5798
also true of base 2: The lowest order “bit,” (binary digit), on the far right, and are
numbered starting from 0. Thus, when sixteen bits are available, they are numbered 0
to 15 from right to left — because each bit on its own represents the quantities 2
0
through 2
15
.
Bit patterns as used here do not represent quantities. Rather, the values of the
individual bits (0 or 1) turn features off and on (respectively). Thus, when the
documentation refers to Bit 5 as controlling feature X, this means that feature X is
“enabled” when Bit 5 is set to 1.
Base 16 used for notational purposes
Straight base 2 notation (a long string of 0s and 1s) is considered to be too unwieldy
to be useful to the human eye as it is too easily prone to misrepresentation and
misinterpretation. Hexadecimal (base 16) notation is used to conveniently specify the
bit patterns for the signals that use them (
i.e.,
the
Config
and
SignalA
n
signals).
Hexadecimal groups all sixteen bits into four sets of four bits each, assigning the
base 10 digits 0 to 9 plus the first six letters of the alphabet A to F to the sixteen
possible combinations of the four bits.
For example, the sixteen-bit (base 2) pattern
0 0 0 0 0 0 0 1 1 1 0 1 0 1 0 1
can be broken into the four four-bit sets
0000
0001
1101
0101
which get assigned to them the four hexadecimal “hex digits”
0
1
D
5
Note that
D
stands for the quantity we normally express in base 10 as thirteen (13).
Therefore, the above bit pattern is referred to conveniently as
$01D5
, or since
leading zeros are optional in any base,
$1D5
. The missing (high-order) bits are
assumed to be 0000. Although $1D5 represents a quantity — which happens to be
four hundred sixty-nine (469) in base 10 — again, we are only interested in bit
patterns
here, not the quantities they may represent.
Standard e-mail Address Format
The format is the standard:
<account name>
@
<IP address | domain name>
(All three parts are required.)
Sender’s e-mail Address
There is no signal for setting the sender’s e-mail address, so this part of the “From:”
header is discussed here.
The actual sender address
is specified once, in the e-Mailer signal block definition,
and that value is used for all mail generated from that signal block. An address must
be supplied to log in to the SMTP server in order to send mail. Therefore, this value
may not be null (blank). The initial value of this setting (for a newly defined e-mailer
signal block) is null. However, at run-time, a null value is replaced with the value:
anonymous@unknown
