Rice Lake SCT-20, Technical Manual

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Operation
© Rice Lake Weighing Systems ● All Rights Reserved 55
In the event of negative weight, the first character on the left acquires the value « - » (minus sign - ASCII 45).
In the event of error or alarm, the 6 gross weight characters are replaced by messages. See
Table 3.5 on page 29 .
Fast Transmission Via External Contact: A single string can be transmitted by closing a digital input, not exceeding 1 sec.
See Section 2.4 on page 16 and Section 2.10 on page 24 .
3.14 Continuous Transmission Protocol
Using this protocol, the instrument transmits, in continuous mode, the weight to remote displays; the communication string is
transmitted 10 times per second. The communication modes available are ( Section 2.4 on page 16 ):
•

: remote display shows the net or gross weight, depending on the remote display setting.
•

: remote display shows the net or gross weight, depending on the remote display setting.
•

:
The instrument sends the following string to the remote display:
• &NxxxxxxLyyyyyy\ckckCR
In the event of negative weight, the first character on the left acquires the value « - » (minus sign - ASCII 45).
If the protocol on

has been set, the decimal point at the position shown on the instrument's display can also be
transmitted. In this case, if the value exceeds 5 digits, only the 5 most significant digits are transmitted, while if the value is
negative, no more than the 4 most significant digits are transmitted. In both cases, however, the decimal point shifts
consistently with the value to display.
If

has been set, in addition to what is stated in

protocol, the instrument transmits the prompt net every 4
seconds in the gross weight field, when the instrument is in net mode. See Section 3.1 on page 28 .
In case weight value is under -99999, the minus sign (-) is sent alternated with the most significant figure.
In the event of error or alarm, the 6 characters of the gross and net weight are replaced by the messages found in
Table 3.5 on
page 29 .
ckck
2 ASCII control characters calculated considering that the characters between
&
and
\
are excluded. The control value is
obtained by carrying out the XOR (or exclusive) operation for the 8 bit ASCII codes of the characters considered. A charac -
ter expressed in hexadecimal is thus obtained, with 2 digits which may acquire values from
0
to
9
and from
A
to
F
.
ckck
is the ASCII code of the two hexadecimal digits.
CR 1 character for string end (13 ASCII).
Data Definition
& 1 character of string start (38 ASCII)
N 1 reference character for net weight. (78 ASCII)
xxxxxx 6 ASCII characters for net or peak weight if present (48 ÷ 57 ASCII)
L 1 reference character for gross weight (76 ASCII)
yyyyyy 6 ASCII characters for gross weight (48 ? 57 ASCII).
\ 1 character for separation (92 ASCII)
ckck
2 ASCII control characters calculated considering that the characters between
&
and
\
are excluded
The control value is obtained by carrying out the XOR (or exclusive) operation for the 8 bit ASCII codes of the characters consid -
ered. character expressed in hexadecimal is thus obtained, with 2 digits which may acquire values from
0
to
9
and from
A
to
F
.
ckck
is the ASCII code of the two hexadecimal digits.
CR character for string end (13 ASCII).
Table 3-50. Continuous Transmission Protocol Data Definitions
Data Definition
Table 3-49.

Communication String Definitions (Continued)