SONBEST SM2120B, User Manual

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SM2120B Us er Ma nual
http://www.sonbus.com/
Sha nghai Son
best Industrial Co., Ltd Page3
40103 00 66 Device ID read/write 1~249
40104 00 67 baud rate read/write 0~6
40105 00 68 mode read/write 1~4
40106 00 69 protocol read/write 1~10
3 read and modify device address
(1) Read or query device address
If you don't know the current device address and there is only one device on the bus, you can use the
command FA 03 00 64 00 02 90 5F Query device address.
Device ID Function id Start Address Data Length CRC16
FA 03 00 64 00 02 90 5F
FA is 250 for the general address. When you don't know the address, you can use 250 to get the real
device address, 00 64 is the device model register.
For the correct query command, the device will respond, for example the response data is: 01 03 02
07 12 3A 79, the format of which is as shown in the following table:
Device ID Function id Start Address Model Code CRC16
01 03 02 55 3C 00 01 3A 79
Response should be in the data, the first byte 01 indicates that the real address of the current device is,
55 3C converted to decimal 20182 indicates that the current device main model is 21820, the last two bytes
00 01 Indicates that the device has a status quantity.
(2)Change device address
For example, if the current device address is 1, we want to change to 02, the command is:01 06 00 66
00 02 E8 14 .
Device ID Function id Start Address Destination CRC16
01 06 00 66 00 02 E8 14
After the change is successful, the device will return information: 02 06 00 66 00 02 E8 27 , its format
is parsed as shown in the following table:
Device ID Function id Start Address Destination CRC16
01 06 00 66 00 02 E8 27
Response should be in the data, after the modification is successful, the first byte is the new device
address. After the general device address is changed, it will take effect immediately. At this time, the user
needs to change the query command of the software at the same time.
4 Read and Modify Baud Rate
(1) Read baud rate
The device default factory baud rate is 9600. If you need to change it, you can change it according to
the following table and the corresponding communication protocol. For example, read the current device's
baud rate ID, the command is:01 03 00 67 00 01 35 D5 , its format is parsed as follows.
Device ID Function id Start Address Data Length CRC16
01 03 00 67 00 01 35 D5
Read the baud rate encoding of the current device. Baud rate encoding: 1 is 2400; 2 is 4800; 3 is 9600;
4 is 19200; 5 is 38400; 6 is 115200.
For the correct query command, the device will respond, for example the response data is: 01 03 02
00 03 F8 45, the format of which is as shown in the following table:
Device ID Function id Data Length Rate ID CRC16
01 03 02 00 03 F8 45