Set_Parameter command (ID 82hex)
writes parameter values to non-volatile memory. You can use it to set the operational
parameters of the GMP231. Depending on the change, the functionality of the GMP231 may not
change immediately.
The length of the invoke message varies depending on the data length. The master must write as many bytes as indicated in the frame length of the invoke message. If the master tries to write a longer or shorter message, GMP231 rejects the message.
Table 1. Set_Parameter invoke message
Message segment |
Length |
Content |
I2C address |
1 byte |
I2C address (write) |
Command ID |
1 byte |
Always 82hex |
Device address |
1 byte |
See Table 2. |
Frame length |
1 byte |
Varies according to data length,
07hex ... 38hex. |
Data |
1 byte |
Parameter ID |
|
1 ... 50 bytes |
Parameter value |
Checksum |
2 bytes |
See Checksum. |
Table 2. Set_Parameter response message
Message segment |
Length |
Content |
I2C address |
1 byte |
I2C address (read) |
Status |
1 byte |
See Status byte. |
Command ID |
1 byte |
Always 82hex |
Device address |
1 byte |
See Table 2. |
Frame length |
1 byte |
Always 08hex. |
Data |
1 byte |
Parameter ID |
|
1 byte |
Return code. See the following table. |
Checksum |
2 bytes |
See Checksum |
Table 3. Set_Parameter return codes
Code |
Meaning |
0 |
Ok |
1 |
Unknown parameter ID |
2 |
Not writeable parameter |
3 |
Value field too long |
4 |
Value field too short |
5 |
Data value not accepted |
6 |
Incorrect message length |