IC-Module for EtherNet/IP
26 / 137
4.6 SDI - Serial Data Interface
The serial data interface allows the application to access the
individual Memory Register via the Modbus-RTU protocol. This
allows you to configure the KUNBUS-IC automatically and to write
process data in the input registers or to read it from the output
registers.
To connect the cables, you have the following options:
– Connect the cables directly with the UART inputs of the microprocessor
on the main board
– Convert the signals to standardised levels using level converters or
interface ICs. Afterwards, place the converted levels onto connectors for
connecting a PC or terminal.
In addition to RX and TX pins, the IC also has a transmit enable TE
output. This makes it possible to connect not only an RS232 driver
but also RS485 or RS422 driver. An example circuit diagram for
RS485 can be found in appendix 2, the RS232 connection must be
made in the same way as for the CDI example circuit diagram.
We deliver the Module to you with the following default settings to
enable access via the SDI :
• automatic baudrate detection
• 8 data bits
• 1 stop bit
• Even parity (Even)
Automatic bitrate detection means that the module tests the following
bitrates until it has received a correct Modbus-RTU telegram:
• 2400 bit/s
• 4800 bit/s
• 9600 bit/s
• 19200 bit/s
• 38400 bit/s
• 57600 bit/s
• 115200 bit/s
Components