Specifications
• Set Modbus TCP/RTU to On. Type the port number on which the connected Modbus TCP Master
initiates communication, by default 504, into “My TCP Port” field.
• Select how you want to translate Modbus addresses to RipEX IP addresses (using mask or table).
Set the UDP interface to Terminal server (TS1-TS5). Set the same TS for remote RipEX’s too.
Select how you want to translate Modbus addresses to RipEX IP addresses (using mask or table). Set
the UDP interface to Terminal server (TS1-TS5). Set the same TS for remote RipEX’s too.
Note
The maximum number of concurrent TCP/IP connections between a Modbus TCP device
and RipEX is set to 10 due to limited computing capacity. (Note: The number of concurrently
open TCP/IP connections can be increased using CLI if necessary.) Modbus TCP Master
must be set to not open more than 10 TCP/IP connections at any given time.
To set up RipEX connected to Modbus TCP Slave:
• Modbus TCP/RTU - Off
• Terminal Servers - On
• Set the Terminal Server (see RipEX Master settings) to TCP and set My Port to 504. Use the address
of the connected Modbus Slave as the destination IP and fill in the destination port number which
the connected Modbus Slave device scans for incoming communication.
• Set Protocol to UNI and Mode of Connected device to Slave.
8.4. Master - Modbus TCP, slaves - Modbus RTU
Note - Only works in Router mode.
Master establishes a local TCP connection to RipEX using Modbus TCP protocol, as described in chap.
3. A packet is securely sent over the Radio network to RipEX to which the destination Slave is connected
by COM port. The RipEX translates the packet to Modbus RTU format and sends it to the connected
Slave using Modbus RTU protocol.
RS232
ModbusRTU
S
RS232
ModbusRTU
S
S
RS232
ModbusRTU
S
RS485
ModbusRTU
S
ETH
ModbusTCP
LocalTCP
connection
M
Fig. 8.5: Modbus TCP - RTU
To set up RipEX connected to Modbus TCP Master:
RipEX Application notes – © RACOM s.r.o.46
Modbus TCP/RTU