Mikroelektronika MIKROE-442 Datenbogen

444

mikoBasic PRO for dsPIC30/33 and PIC24

MikroElektronika

RS485Slave_Receive

RS485Slave_Send

sub procedure RS485Slave_Receive(dim byref data as byte[20])

Description Receives messages from Master. If Slave address and Message address field don’t match then the 

message will be discarded. Messages are multi-byte, so this routine must be called for each byte 

received.

Parameters - 

data_buffer

: 6 byte buffer for storing received data, in the following manner: 

- 

data_buffer[0..2]

: message content 

- 

data_buffer[3]

: number of message bytes received, 1–3 

- 

data_buffer[4]

: is set to 255 when message is received 

- 

data_buffer[5]

: is set to 255 if error has occurred 

The routine automatically adjusts 

data[4]

 and 

data[5]

 upon every received message. These flags 

need to be cleared by software.

Nothing.

MCU must be initialized as a Slave for RS-485 communication. See RS485Slave_Init.

dim msg as byte[8]

...

RS485Slave_Read(msg)

None

sub  procedure  RS485Slave_Send(dim  byref  data  as  byte[20],  dim  datalen  as 

byte)

Description Sends message to Master. Message format can be found at the bottom of this page.
Parameters - 

data_buffer

: data to be sent 

- 

datalen

: number of bytes for transmition. Valid values: 0...3. 

Nothing.

MCU must be initialized as a Slave for RS-485 communication. See RS485Slave_Init. It is the user’s 

responsibility to ensure (by protocol) that only one device sends data via 485 bus at a time.

dim msg as byte[8]

...

‘ send 2 bytes of data to the Master

RS485Slave_Send(msg, 2)

None