USB-I/O Interface Adapter GPIO-24. Programmer's Reference Manual.
8.5. GPIO_GET_CMP_CFG (0x10)
The GPIO_GET_CMP_VAL command retrieves the comparison results of GPIO-24 adaptor comparators COMP0 and COMP1.
GPIO_GET_CMP_VAL Command
| Byte 0 | GPIO_GET_CMP_VAL | Command ID (0x22). |
| Byte 1 | ECHO | Echo to associate a command with the response. |
| Bytes 2..7 | Reserved | Reserved (must be 0). |
Command is an 8-byte array of the following format:
- Byte 0: GPIO_GET_CMP_VAL (0x22)
This byte contains command ID (command type). It should be set to 0x22.
- Byte 1: ECHO
This byte is used to associate a response received from GPIO-24 adapter with a specific command. Response will contain exactly the same value in its echo byte.
- Bytes 2..7: Reserved
These bytes are reserved for future usage and must be set to 0.
For convenience GPIO_GET_CMP_VAL_CMD structure is declared in reports.h file.
GPIO-24 adapter sends GPIO_GET_CMP_VAL response after command execution. The results of comparison for GPIO-24 adaptor comparators COMP0 and COMP1 are specified inside the response.
GPIO_GET_CMP_VAL Response
| Byte 0 | GPIO_GET_CMP_VAL | Response ID (0x22). |
| Byte 1 | ECHO | Echo to associate a response with a specific command. |
| Byte 2 | ST | Status of the command execution. |
| Byte 3 | CMP_0_OUT | The result of comparison for CMP0 comparator. |
| Byte 4 | CMP_1_OUT | The result of comparison for CMP1 comparator. |
| Byte 5..7 | Reserved | Reserved |
Response is an 8-byte array of the following format:
- Byte 0: GPIO_GET_CMP_VAL (0x22)
Response ID (response type). This byte will contain 0x22.
- Byte 1: ECHO
This byte is used to associate a response received from GPIO-24 adapter with a specific command. Response will contain exactly the same value in its echo byte.
- Byte 2: ST
Status of the command execution.
- Byte 3: CMP_0_OUT
The result of comparison for CMP0 comparator.
The comparator output can be inverted with Bit 5: CMP0_INV in Byte 2: CMP_CFG of GPIO_SET_CMP_CFG command.
If CMP0_INV = 1, CMP0 comparator output is inverted:
If CMP0_INV = 0, CMP0 comparator output is not inverted:1, if VIN+ < VIN-;
0, if VIN+ > VIN-.
1, if VIN+ > VIN-;
0, if VIN+ < VIN-.
- Byte 4: CMP_1_OUT
The result of comparison for CMP1 comparator.
The comparator output can be inverted with Bit 4: CMP1_INV in Byte 2: CMP_CFG of GPIO_SET_CMP_CFG command.
If CMP1_INV = 1, CMP1 comparator output is inverted:
If CMP1_INV = 0, CMP1 comparator output is not inverted:1, if VIN+ < VIN-;
0, if VIN+ > VIN-.
1, if VIN+ > VIN-;
0, if VIN+ < VIN-.
- Bytes 5..7: Reserved
These bytes are reserved for future usage.
