![Rice Lake SCT20-AN Скачать руководство пользователя страница 57](http://html1.mh-extra.com/html/rice-lake/sct20-an/sct20-an_technical-manual_1454277057.webp)
Operation
© Rice Lake Weighing Systems
●
All Rights Reserved
53
• Incorrect reception or full scale equal to zero: &&aa?\ckckCR
For 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)
For correct calibration the read value will be 020000.
Keypad Lock (Access Protection To The Instrument)
The PC transmits: $aaKEYckckCR$01KEY56CR
Possible instrument responses:
• Correct reception: &&aa!\ckckCR
• Incorrect reception: &&aa?\ckckCR
Keypad Unlock
The PC transmits: $aaFREckckCR$01FRE50CR
Possible instrument responses:
• Correct reception: &&aa!\ckckCR
• Incorrect reception: &&aa?\ckckCR
Display And Keypad Lock
The PC transmits: $aaKDISckckCR$01KDIS14CR
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 this 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
Table 3-45. Example Check Sum Calculation (ASCII)
Содержание SCT20-AN
Страница 1: ...SCT Weight Transmitter 20 Series Technical Manual PN 131128 Rev F June 26 2018...
Страница 64: ......