SMS-531 User’s Manual v1.1
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6. SMS-531 Modbus Address Table
The Modbus function codes supported in the SMS-531 are 1, 2, 3, 4, 5, 6, 15 and
16. The Modbus address distribution is as the following table.
(1)
Coil Status (Function Code: 1, 5, 15)
Address
Data
Address
Description
Attribute
00001 ~
00128
0x0 ~
0x7F
Transmitting the alarm SMS and voice according 0~127
alarm
R/W
00129
0x80
Transmitting the SMS dynamically
R/W
00200
0xC7
=1, Clearing the received SMS buffer
R/W
00201
0xC8
=1, Clearing the transmitting SMS buffer
R/W
00210
0xD1
=1, Saving the data of the holding registers to Flash
(Address: 40001~40256)
R/W
Note: Using function code 15 to transmit the alarm SMS and voice according 0~127
alarm, maximum quantity of DO is up to 16.
(2)
Discrete Input (Function Code: 2)
Address
Data
Address
Description
Attribute
10001
0x0
The status of transmitting SMS buffer
0
：
No
1
：
Overflow
R
10002
0x1
The indication of the received SMS
0
：
No received SMS
1
：
Having received SMS
R
10003
0x2
The status of SD card
0
：
No SD card or Error
1
：
Normal
R
