USB-I/O Interface Adapter GPIO-24. Programmer's Reference Manual.
11.5. GPIO_SET_PLS_CNT_LIMIT (0x28)
The GPIO_GET_PLS_CNT_LIMIT command retrieves pulse counter limits – time period or threshold number of pulses – for Time Based Mode and Pulse Based Mode, correspondingly.
GPIO_GET_PLS_CNT_LIMIT Command
| Byte 0 | GPIO_GET_PLS_CNT_LIMIT | Command ID |
| Byte 1 | ECHO | Echo to associate command with the response |
| Byte 2 | PLS_CNT_NUMBER | ID number of the counter, which limit will be retrieved. |
| Byte 3 | LIMIT_TYPE | Type of the counter limit (time period or threshold number of pulses) |
| Bytes 4..7 | Reserved | Reserved |
Command is an 8-byte array of the following format:
- Byte 0: GPIO_GET_PLS_CNT_LIMIT (0x29)
This byte contains command ID (command type). It must be set to 0x29.
- Byte 1: ECHO
This byte can be 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: PLS_CNT_NUMBER
The ID number of the pulse counter:
0 – pulse counter on A.3 pin;
1 – pulse counter on A.4 pin.
- Byte 3: LIMIT_TYPE
The type of value to be retrieved:
GPIO_PLS_CNT_VAL_PULSES (0) – the command retrieves the threshold number of pulses.
GPIO_PLS_CNT_VAL_TIME (1) – the command retrieves the time period in units of 10 ms.
- Bytes 4..7: Reserved
These bytes are reserved for future usage and must be set to 0.
For convenience GPIO_GET_PLS_CNT_LIMIT_CMD structure is declared in reports.h file.
GPIO-24 adapter sends GPIO_GET_PLS_CNT_LIMIT response after command execution. Pulse counter limit is specified inside the response.
GPIO_GET_PLS_CNT_LIMIT Response
| Byte 0 | GPIO_GET_PLS_CNT_LIMIT | Response ID |
| Byte 1 | ECHO | Echo to associate command with the response |
| Byte 2 | ST | Command execution status |
| Byte 3 | PLS_CNT_NUMBER | The number of pulse counter |
| Byte 4 | LIMIT_TYPE | The type of limit |
| Byte 5 | LIMIT[2] | Counter limit (time period or threshold number of pulses) |
| Byte 6 | LIMIT[1] | |
| Byte 7 | LIMIT[0] |
Response is an 8-byte array of the following format:
- Byte 0: GPIO_GET_PLS_CNT_LIMIT (0x29)
Response ID (response type). This byte will contain 0x29.
- Byte 1: ECHO
Echo byte copied from the corresponding command. It can be used to associate the response with the specific command.
- Byte 2: ST
Status of the command execution:
GPIO_ST_SUCCESS (0x00) – Pulse counter limit has succesfully been retrieved;
GPIO_ST_INVALID_PLS_CNT_NUMBER (0x0A) – Invalid ID of the pulse counter has been specified (only 0 and 1 values are valid);
GPIO_ST_INVALID_PARAMETER (0x0B) – Unsupported pulse counter limit type has been specified.
- Byte 3: PLS_CNT_NUMBER
The ID number of the pulse counter:
0 – pulse counter on A.3 pin;
1 – pulse counter on A.4 pin.
- Byte 4: LIMIT_TYPE
The type of value specified in Bytes 5..7: LIMIT:
GPIO_PLS_CNT_VAL_PULSES (0) – Bytes 5..7: LIMIT contain the threshold number of pulses.
GPIO_PLS_CNT_VAL_TIME (1) – Bytes 5..7: LIMIT contain the time period in units of 10 ms.
- Bytes 5..7: LIMIT
These bytes contain pulse counter limits.
If Byte 4: LIMIT_TYPE = GPIO_PLS_CNT_VAL_TIME (1) – Bytes 4..6: LIMIT define the time period in units of 10 ms up to 16,777,215 (167,772,150 ms or 46.5 h).
If Byte 4: LIMIT_TYPE = GPIO_PLS_CNT_VAL_PULSES (0) – Bytes 4..6: LIMIT define the threshold number of pulses up to 16,777,215.
Byte 5: LIMIT[2] – least significant byte (low byte) of a pulse counter limit.
Byte 6: LIMIT[1] – middle byte of threshold a pulse counter limit.
Byte 7: LIMIT[0] – most significant byte (high byte) of a pulse counter limit.
For convenience GPIO_GET_PLS_CNT_LIMIT_RSP structure is declared in reports.h file.
