General purpose flash memory
XLR PRO Radio Frequency (RF) Modem User Guide
66
When a GPM command is sent to a radio via a unicast, the receiving radio will unicast a response back to the
requesting radio's source endpoint specified in the request packet. No response is sent for broadcast requests. If the
source endpoint is set to the DIGI_DEVICE endpoint (0xE6) or explicit API mode is enabled on the requesting radio,
then a GPM response will be output as an explicit API RX indicator frame on the requesting node (assuming API mode
is enabled).
The format of the response is similar to the request packet:
The following commands exist for interacting with GPM:
•
PLATFORM_INFO_REQUEST (0x00):
A PLATFORM_INFO_REQUEST frame can be sent to query details of the GPM
structure.
•
PLATFORM_INFO (0x80):
When a PLATFORM_INFO_REQUEST command request has been unicast to a node, that
node will send a response in the following format to the source endpoint specified in the requesting frame.
6
2
GPM_NUM_BYTES
Number of bytes in the GPM_DATA field, or in the case of a
READ, the number of bytes requested. Specify multi-byte
parameters using big-endian byte ordering
8
varies
GPM_DATA
Payload
byte offset
Number of
bytes
Field name
General field description
0
1
GPM_CMD_ID
This field will be the same as the request field
1
1
GPM_STATUS
Status indicating whether the command was successful
2
2
GPM_BLOCK_NUM
The block number addressed in the GPM. Specify multi-byte
parameters using big-endian byte ordering.
4
2
GPM_START_INDEX
The byte index within the addressed GPM block. Specify multi-
byte parameters using big-endian byte ordering.
6
2
GPM_NUM_BYTES
The number of bytes in the GPM_DATA field. Specify multi-byte
parameters using big-endian byte ordering
8
varies
GPM_DATA
Field name
Command-specific description
GPM_CMD_ID
Set to PLATFORM_INFO_REQUEST (0x00).
GPM_OPTIONS
Set to 0. This field is unused for this command.
GPM_BLOCK_NUM
Set to 0. This field is unused for this command.
GPM_START_INDEX
Set to 0. This field is unused for this command.
GPM_NUM_BYTES
Set to 0. This field is unused for this command.
GPM_DATA
No data bytes should be specified for this command.
Payload
byte offset
Number of
bytes
Field name
General field description