ASCII format command and reply messages contain only the set of printable ASCII characters as
described in the following list of legal characters:
*
~
-
+
.
=
>
<
0-9
a-z
Asterisk
Tilde
Minus
Plus
Period
Equal
Greater than
Less than
Numbers zero through nine
Letters ‘a’ through ‘z’ (not sent in replies)
A-Z
Letters ‘A’ through ‘Z’
#
?
{
!
^
|
}
@
&
%
$
‘ ‘
Pound sign
Question mark
Left brace
Exclamation mark
Circumflex
Bar
Right brace
At/each
And/ampersand
Percent
Dollar sign (used before a command to stop, or suspend, continuous PPT trans-
missions while manually typing commands)
Space, or Blank
5.6
BINARY FORMAT REPLIES
The binary format reply is only used for the pressure reading commands
P3
and
P4
. It consists of a
1 byte header character, 4 bytes data, an optional 1 byte cyclic check sum, and 1 byte <cr> character.
For the binary format replies, the address type, error condition and data sign are encoded into the
single header character as shown in Table 5.1 below.
Header
Assigned
Error
Data
Alternate
Characters
Address
Condition
Sign Hdr.
RS-485 only
(1)
{
}
!
@
^
&
|
%
Yes
Yes
Yes
Yes
N u l l
N u l l
N u l l
N u l l
No
No
Yes
Yes
No
No
Yes
Yes
+
-
+
-
+
-
+
-
DC1 (ctrl Q)
DC2 (ctrl R)
DC3 (ctrl S)
DC4 (ctrl T)
none
none
none
none
(1) See
M=
command and Table 9.2 for ASCII hex value
Table 5.1—Header Description for Binary Format Pressure Readings
3 1
