RabbitCore eDisplay OP7200, Руководство пользователя

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User’s Manual 157
Reads a string from the specified device and register. Waits for results.
This function will
check device
information to determine that the peripheral board is connected to a master.
PARAMETERS
handle
is an address index to device information. Use
rn_device()
or
rn_find()
to establish the
handle.
regno
is the command register number as designated by each device.
recdata
is a pointer to the address of the string to read from the device.
datalen
is the number of bytes to read (0–15).
NOTE: A data length of 0 will transmit the one-byte command register number.
RETURN VALUE
The status byte from the previous command. -1 means that device information indicates the peripheral
board is not connected to the master, and -2 means that the data length was greater than 15.
SEE ALSO
rn_write
Sends a reset sequence to the specified peripheral board. The reset takes approximately 25 ms before the
peripheral board will once again execute the application. Allow 1.5 seconds after the reset has completed
before accessing the peripheral board. This function will check peripheral board information to deter-
mine that the peripheral board is connected to a master.
PARAMETERS
handle
is an address index to device information. Use
rn_device()
or
rn_find()
to establish the
handle.
resettype
describes the type of reset.
0 = hard reset—equivalent to power-up. All logic is reset.
1 = soft reset—only the microprocessor logic is reset.
RETURN VALUE
The status byte from the previous command. -1 means that device information indicates the peripheral
board is not connected to the master.
int rn_read(int handle, int regno, char *recdata,
int datalen);
int rn_reset(int handle, int resettype);