User manual

444
mikoBasic PRO for dsPIC30/33 and PIC24
MikroElektronika
RS485Slave_Receive
RS485Slave_Send
Prototype
sub procedure RS485Slave_Receive(dim byref data as byte[20])
Description Receives messages from Master. If Slave address and Message address eld 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 ags
need to be cleared by software.
Returns Nothing.
Requires MCU must be initialized as a Slave for RS-485 communication. See RS485Slave_Init.
Example
dim msg as byte[8]
...
RS485Slave_Read(msg)
Notes None
Prototype
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.
Returns Nothing.
Requires 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.
Example
dim msg as byte[8]
...
‘ send 2 bytes of data to the Master
RS485Slave_Send(msg, 2)
Notes None