DPR-400 User Manual Rev_01 Firmware V-1.0
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The unit offers MODBUS functionality in the following forms:
-RS485 serial port, adjustable baud rate between 2400 and 115200 baud
-Modbus TCP/IP over Ethernet port
MODBUS features of the unit:
-Data transfer mode: RTU
-Serial data: adjustable baud rate, 8-bit data, no parity, 1 bit stop
-Supported functions:
-Function 3 (read multiple register)
-Function 6 (write single register)
-Function 16 (read multiple register)
Each register consists of 2bytes (16 bits). Larger data structures are provided using multiple registers.
Each device in the Modbus communication network must have a distinct address. The unit supports
addresses in the range 1-247.
Modbus Address:
May be set as a value between 1 and 247.
RS-485 Enabled:
Must be set as 1 (or the parameter box must be checked).
RS-485 Baud Rate:
Adjustable between 2400 and 115200 bauds. Every device in the communication
group must have the same baud rate.
Increasing the baud rate provides faster communication at a shorter communication distance. Decreasing
the baud rate allows communication at longer distances with a slower rate of data transmission.
9600 bauds communication speed can be reached with a 120ohm balanced cable at 1200m distance.
Modbus Slave Address:
May be set to any value between 1 and 240. If there is only one device at a
given IP address, it is advised to set this parameter to 1.
Ethernet Enabled:
This parameter must be set to 1 in order for the Ethernet port to be active.
Modbus TCP/IP Port:
This parameter is typically set to 502. However, the device can operate with any
port address.
User IP Mask:
These parameters are used to control incoming IPv4 input to the device.
Ethernet Network IP:
If the device is required to take a dynamic IP, this parameter must be left at its
default value, 0.0.0.0. In order to give the device a static IP, the desired Ip address must be entered here.
Ethernet Gateway IP:
Must be set according to your router.
Ethernet Subnet Mask:
Must be set according to your router.
Please refer to
Ethernet Configuration Guide
for detailed information regarding Ethernet features.
14. MODBUS COMMUNICATIONS
Each device in the RS-485 serial network must have a distinct
address. Otherwise, Modbus communication will not function.
14.1. PARAMETERS FOR RS-485 MODBUS COMMUNICATION
14.2. ETHERNET MODBUS-TCP/IP PARAMETERS