Rice Lake SCT-10 - Manual (Page 49)

Operation 45
in which:
t = gross weight identification code (116 ASCII).
xxxxxx = 6 characters to indicate the current weight value.
In case of correct calibration, the read value must be equal to test weight.
Example: Calibration for instrument with address 1 and test weight of 20000 kg:
query: $01s02000070(Cr) response: &01020000t\77(Cr)
In case of correct calibration the read value has to be “020000”.
Keypad Lock (Access Protection To The Instrument)
The PC transmits: $aaKEYckckCR
Possible instrument responses:
- correct reception: &&aa!\ckckCR
- incorrect reception: &&aa?\ckckCR
Keypad Unlock
The PC transmits: $aaFREckckCR
Possible instrument responses:
- correct reception: &&aa!\ckckCR
- incorrect reception: &&aa?\ckckCR
Display And Keypad Lock
The PC transmits: $aaKDISckckCR
Possible instrument responses:
- correct reception: &&aa!\ckckCR
- incorrect reception: &&aa?\ckckCR
Check-Sum Calculation
The two ASCII control characters (ckck) are the representation of a hexadecimal
digit in ASCII characters. The check digit is calculated by performing the
operation XOR (exclusive or) 8-bit ASCII codes of the only part of the
underlined string.
The procedure to calculate the check- sum is the following:
• Consider only the string characters highlighted with underlining;
• Calculate the EXCLUSIVE OR (XOR) of the ASCII codes for the
characters;
Example:
• The result of the XOR operation expressed in hexadecimal notation is made
up of 2 hexadecimal digits (numbers from 0 to 9 or letters from A to F). In
this case the hexadecimal code is 0x75.
• The check-sum inserted in the strings transmitted is made up of the 2
characters which represent the result of the XOR operation in hexadecimal
notation (in our example the character " 7 " and the character " 5)
Character
Decimal ASCII
Code
Hexadecimal ASCII
Code
Binary ASCII
Code
0 48 30 00110000
1 49 31 00110001
t 116 74 01110100
XOR = 117 75 01110101