NOVUS Web Server – WS10 - Manual (Page 24)

Web Server – WS10
NOVUS AUTOMATION 24/33
MODBUS RTU NETWORK CONFIGURATION – WS10 AS SLAVE
The WS10 can be configured to act as a Modbus RTU slave on a serial port. When the WS10 is a Modbus RTU master on one serial port and slave
on the other serial port, it can be used as a Modbus RTU concentrator.
Assignment of unique addresses to the WS10 registers are defined by the user in the MAP.CFG file, as described in section “Registers Address
Map for Modbus TCP and Modbus RTU-Slave”.
Read requests are promptly answered by the WS10 from the data in its memory. When the WS10 receives a write command to a memory register
that is associated to an external Modbus device (on the network that the WS10 is the master), it executes the write operation on this device. The
WS10 will only confirm the write operation to the master when the confirmation from the slave on the other network is received.
The slave Modbus function is enabled when the file MODBUS2.CFG is installed. Follows an example of this file:
[Config]
Serial=2
Flowctrl=2
De485=0
Baudrate=19200
Parity=0
Wordlen=8
Stopbits=1
Address=1
Timeout=20
At the [Config] section the serial port parameters are defined. The Address parameter defines the slave
address of the WS10 on the network.
Section Parameter Values Description
Serial 1 or 2 Number of the serial port assigned to the slave Modbus RTU function.
Flowctrl 0 or 2
Serial port flow control configuration:
0: Now flow control
2: RTS/CTS flow control (typical when RS485 or RS232 with external RS232 / 485 converter).
De485 0, 1 or 2
RS485 mode configuration.
0: RS232 with external RS232 / 485 converter.
1: RS485
2: RS232
Baudrate
300, 600, 1200, 2400,
4800, 9600, 19200,
38400
Serial port baud rate.
Parity 0, 1 or 2
Serial port parity.
0: No parity; 1: Even; 2: Odd.
Wordlen 7 or 8 Number of bits per byte.
Stopbits 1 or 2 Number of stop bits.
Address 1 to 247 WS10 slave address.
Config
Timeout 1 to 30000
Silent interval between Modbus frames, in ms. When a frame is received, it is considered complete
after a silent interval with at least this value. Typical value: 20. Consider adjusting this value if WS10 is
not responding a significant number of requests from master.