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and other functions. The data storage area allocation and address coding range are shown in
"Table 3.1".
Table 3.1 Data storage area address table
3.1.4 System diagnosis area
The system diagnosis is divided into two parts. The first part: Address 0x2000-0x200F
has 16 words i.e. 256 bits, which is the "slave station error indication area". The bits
numbered 1-247 correspond to the slave stations with address 1-247. , The bits numbered
248-256 are reserved. When an error occurs in the slave communication, the bit
corresponding to the slave address is set to 1. The corresponding error indication bit will be
automatically cleared after the slave station returns to normal. The data encoding format is
shown in "Table 3.2".
Table 3.2 Coding format of slave error indication area
No.
Storage
category
Description
Storage capacity
Address range
1
Zone 0
coil
8192 Bit
0x0000~0x1FFF
2
Zone 1
Discrete input
8192 Bit
0x0000~0x1FFF
3
Zone 3
Input register
2048 Word
0x0000~0x07FF
4
Zone 4
Holding register
2048 Word
0x0000~0x07FF
5
Zone 3
System diagnosis
263 Word
0x2000~0x2106
Address
0x2000
BIT
Bit15 Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Bit
number
16
15
14
13
12
11
10
9
BIT
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Bit
number
8
7
6
5
4
3
2
1
Address
0x2001
BIT
Bit15 Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
Bit
number
32
31
30
29
28
27
26
25
BIT
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
Bit
number
24
23
22
21
20
19
18
17