Rice Lake SCT-10 - Manual (Page 50)

46 SCT Weight Transmitter Operator’s Manual
3.8 Fast Continuous Transmission Protocol
This protocol allows for continuous serial output at high update frequencies. Up
to 80 strings per second are transmitted (with a minimum transmission rate of
9600 baud). See “Filter Settings” on page 19 for limitations.
Following communication modes available (see Section 2.4 “Analog Output” on
page 21):
• NOd t: communication compatible with TX RS-485 instruments;
• NOd td: communication compatible with TD RS-485 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 “Alarm Descriptions” on page 33.
• 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 “Alarm Descriptions” on page 33.
Fast Transmission Via External Contact: A single string can be transmitted by
closing a digital input, not exceeding 1 second. (see Section 2.6 “Outputs And
Inputs Configuration” on page 26 and Section 2.4 “Analog Output” on page 21).
3.9 Continuous Transmission Protocol To Remote Displays
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 2.4 “Analog Output”
on page 21):
• rl P: remote display shows the net or gross weight, depending on the remote
display setting.