This command starts the Fast Response Command (FRC) process supported by IQRF OS. It allows quick and using only one request to collect the same type of information (data length) from multiple Nodes in the network. The type of the collected information is specified by a byte called the FRC command. Currently, IQRF OS allows collecting either 2 bits from all (up to 239) Nodes, 1 byte from up to 63 Nodes (having logical addresses 1-63), 2 bytes from up to 31 Nodes (having logical addresses 1-31), or 4 bytes from up to 15 Nodes (having logical addresses 1-15). The type of collected data is specified by the FRC command value:
|
Type of collected data |
FRC Command interval |
Reserved interval |
|
|
2 bits |
0x00 - 0x7F |
0x00 - 0x3F |
0x40 - 0x7F |
|
1 byte |
0x80 - 0xDF |
0x80 - 0xBF |
0xC0 - 0xDF |
|
2 bytes |
0xE0 - 0xF7 |
0xE0 - 0xEF |
0xF0 - 0xF7 |
|
4 bytes |
0xF8 - 0xFF |
0xF8 - 0xFB |
0xFC - 0xFF |
When 2 bits are collected, then the 1st bits from the Nodes are stored in the bytes of index 0-29 of the output buffer, 2nd bits from the Nodes are stored in the bytes of index 32-61.
When 1 byte is collected then bytes from each [N] (1-63) are stored in bytes 1-63 of the output buffer.
When 2 bytes are collected then byte pairs for each [N] (1-31) are stored in bytes 2-63 of the output buffer.
When 4 bytes are collected then byte foursomes for each [N] (1-15) are stored in bytes 4-63 of the output buffer.
For more information see IQRF OS manuals. If the [N] does not return an FRC value for some reason, then either returned bits or bytes are equal to 0. This is why it is necessary to code the zero return value into a non-zero one.
The time when the response is delivered depends on the type of the FRC command and used RF mode. Consult IQRF OS guides for the response time calculation and the IQMESH Timing Calculator.
Request
|
NADR |
PNUM |
PCMD |
HWPID |
0 |
1 … n |
|
NADR |
0x0D |
0x00 |
? |
FrcCommand |
UserData |
FrcCommand Specifies data to be collected.
UserData User data that are available at IQRF OS array variable DataOutBeforeResponseFRC at FRC Value event. The length n is from 2 to 30 bytes.
Response
|
NADR |
PNUM |
PCMD |
HWPID |
ErrN |
DpaValue |
0 |
1 … n |
|
NADR |
0x0D |
0x80 |
? |
0 |
? |
Status |
FrcData |
Status Return code of the sendFRC IQRF OS function (typically number of responding [Ns]). See IQRF OS documentation for more information.
FrcData Data collected from the Nodes. Because the current version of DPA cannot transfer the whole FRC output buffer at once (currently only up to 55 bytes), the remaining bytes of the buffer can be read by the next described Extra result command.
The following video depicts a FRC communication in the
IQMESH network.