User`s manual

330
(d) Conversion of error code
• At transmission: The Q series C24 converts an error code for a detected error to 4-digit ASCII code data
(hexadecimal), then sends it beginning with the lowest byte (L). (For 3412H, it is converted to "3412" and
sent beginning with "12".)
• At reception: The Q series C24 converts the first 2 digits of a received error code (4-digit ASCII code data
(hexadecimal)) to 2-byte binary code data as the lower byte, and stores it in the transmission result
storage area. (For "1234" is received, it is converted to 3412H and stored.)
(e) Treatment of sum check code
The data length and the data section after ASCII-BIN conversion are added together and the lowest two bytes
of the resulting binary code data are treated as a sum check code.
• At transmission: The Q series C24 calculates a sum check code using the data length and data section
after ASCII-BIN conversion, then adds it to the transmission message.
• At reception: The Q series C24 calculates a sum check code using the received data length and data
section prior to ASCII-BIN conversion, then checks the received head of the sum-check code using the
code as a lower byte.
(2) Page 309, Section 12.5 explains how Q series C24 processes data
communicated when ASCII-BIN conversion and transparent code designation
are both enabled.
*1
*1
30H+32H+30H+30H+31H+32H+33H+34H+35H+41H+42H+43H=0287H
(H)(L)
05H 30H 32H 31H 32H 33H30H 30H 34H 35H
L
0012
41H
5A
42H 43H
34 BC
87H
L
02H
HH
02
(0002)
(H) (L)
00H , 02H
34H , 12H
BCH , 5AH
E
N
Q
Data section
Buffer memory
Data length
Sum
check
code
(When word units are used)
Transmission data
count/Receive data
count
Transmission data/
receive data
Message
ASCII-BIN conversion
Calculation of sum check code
……
…
(BC3AH)
(0212H)
(0002H)
(H) (L)
15H 33H 34H 06H
L
05H
0
30H 32H
2
31H 32H 30H 32H 80H 02H
1202
HL
30H 30H
00
L
33H 41H
3A
42H 43H
BC
H
31H 32H
3
4
H
12
A
C
K
E
N
Q
00H , 02H
02H , 12H
BCH , 3AH
N
A
K
Transmission
data count/
Receive data
count
Buffer memory (transmission area/reception area)
External device
Q series C24
Transmission
data/receive
data
(Communication of
response massage)
Transmission
result/reception
result
Error code
Starting data
Or
At normal
completion: 0000H
At abnormal
completion: 1234H
Send
Receive
(Data
communication)
Data length Data section
Sum
check
code
Arbitrary data section
Head data
Conversion
Send
Receive
Conversion
……
…
……