DLN_SPI_MASTER_SET_SS Command and Response

The DLN_SPI_MASTER_SET_SS command is used to select a Slave Select (SS) line.

DLN_SPI_MASTER_SET_SS Command

 typedef struct
 {
    DLN_MSG_HEADER header;
    uint8_t port;
    uint8_t ss;
 } __PACKED_ATTR DLN_SPI_MASTER_SET_SS_CMD;

Parameters:

header

Defines the DLN message header DLN_MSG_HEADER. The header contains several predefined fields and is used to identify and route messages. You must fill the following fields before sending the command:

Field	Description
size	The size of the message. Must be equal to the size of the DLN_SPI_MASTER_SET_SS_CMD structure.
msgId	Identifies the message. For the DLN_SPI_MASTER_SET_SS command it must be set to 0x0226. You can use the DLN_MSG_ID_SPI_MASTER_SET_SS constant.
echoCounter	Can be used to link a command to a response. The response will have the same echoCounter value. This field can be any numerical value from 0 to 0xFFFF (65536).
handle	A handle to the DLN-series adapter.

port

A number of the SPI master port to be configured.

ss

An 8-bit mask, containing the value on the SS lines. The bits 4-7 are reserved and must be set to 1. For additional details see SPI Slave Selectionsection.

If you expect slaves to output data, you must ensure that only one slave is activated. If several slaves start outputting data simultaneously, the equipment can be damaged.

If you use Slave Selection, with an external decoder/multiplexer connected, the SS lines are used to encode the number of slave device. The numbers 0 to 14 represent the number of the slave device, while 15 means that no device is selected.

DLN_SPI_MASTER_SET_SS Response

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The adapter sends the DLN_SPI_MASTER_SET_SS response after the DLN_SPI_MASTER_SET_SS command execution. The result field informs a user if a Slave Select (SS) line has been successfully selected.

 typedef struct
 {
    DLN_MSG_HEADER header;
    DLN_RESULT result;
 } __PACKED_ATTR DLN_SPI_MASTER_SET_SS_RSP;

Parameters:

header

Defines the DLN message header DLN_MSG_HEADER. The response header contains the following fields:

Field	Description
size	The size of the message. It is equal to the size of the DLN_SPI_MASTER_SET_SS_RSP structure.
msgId	Contains the message id. For the DLN_SPI_MASTER_SET_SS response it is set to 0x0226. The DLN_MSG_ID_SPI_MASTER_SET_SS constant can be used to check the message ID.
echoCounter	Links a command to a response. The echoCounter value is copied from the respective command header.
handle	A handle to the DLN-series adapter. You can use the handle field to determine the adapter that have sent the response.

result

Contains the result of the command execution. For DLN_SPI_MASTER_SET_SS command DLN-series adapter can return the following result values:

Return Code	Description
DLN_RES_SUCCESS	The SS line has been successfully selected.

DLN_SPI_MASTER_SET_SS Command and Response