Rice Lake Signal Conditioning Transmitter/Indicators - Manual (Page 61)

Operation 57
3.13 Fast Continuous Transmission Protocol
This protocol allows for continuous serial output at high update frequencies. Up to 300 strings per second are
transmitted (with a minimum transmission rate of 38400 baud). See Section 2.9 on page 24 for limitations.
Following communication modes available (see Section 2.9 on page 24):
• NOd t: communication compatible with TX RS485 instruments;
• NOd td: communication compatible with TD RS485 instruments.
• If NOd t is set, the following string is transmitted to PC/PLC: xxxxxxCRLF
in which:
xxxxxx = 6 ASCII characters for gross weight (48 ÷ 57 ASCII).
CR = 1 character of carriage return (13 ASCII).
LF = 1 character of line feed (10 ASCII).
In case of negative weight, the first character on the left acquires the value « - » (minus sign - ASCII 45).
In case of error or alarm, the 6 weight characters are replaced by the messages found in Table 3-1 on
page 34.
• If NOd td is set, the following string is transmitted to PC/PLC: &TzzzzzzPzzzzzz\ckckCR
in which:
& = 1 character of string start (38 ASCII).
T = reference character for gross weight.
P = reference character for gross weight.
zzzzzz = 6 ASCII characters for gross weight (48 ? 57 ASCII).
\ = 1 character of 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 considered. A 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 = 1 character for string end (13 ASCII).
In case of negative weight, the first character on the left acquires the value « - » (minus sign - ASCII 45).
In case of error or alarm, the 6 gross weight characters are replaced by the messages found in the table of the
ALARMS.
Fast Transmission Via External Contact: A single string can be transmitted by closing a digital input, not
exceeding 1 sec. (see Section 2.10 on page 27 and Section 2.9 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. Following communication modes are available (see
Section 2.9 on page 24):
• rL P: remote display shows the net or gross weight, depending on the remote display setting.
• HdrL P: remote display shows the net or gross weight, depending on the remote display setting.
• HdrL Pn:
See following page for more information.
The instrument sends the following string to the remote display:
&NxxxxxxLyyyyyy\ckckCR
in which:
& = 1 character of string start (38 ASCII).
N = 1 reference character for net weight. (78 ASCII).
Note