DPR-400 User Manual Rev_01 Firmware V-1.0
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Structure:
RS-485, isolated.
Connection:
3 wires (A-B-GND). Half duplex.
Baud rate:
2400-115200 baud, selectable.
Data type:
8-bit data, no parity, 1 bit stop
Termination
External 120 ohms required.
Common mode voltage:
-0.5 VDC to +7VDC, internally clamped by transient suppressors.
Max. Distance:
1200m @ 9600 baud (with 120-ohm balanced cable)
200m @ 115200 baud (with 120-ohm balanced cable)
Isolation:
500VAC, 1 minute
Supported protocols:
IEC60870-5-103, Modbus RTU
The RS-485 port provides an effective solution for distant PC connection to enable programming and
monitoring via SCADA software.
RS-485 LINE STRUCTURE
Up to 32 controllers can be connected in parallel in a single RS-485 line. A repeater is required in order to
connect more controllers.
The line must be terminated by 120 ohms on each end.
The cable shield must be grounded at one end only.
A B
A B
A B
A B
120R
120R
3.6. RS-485 PORT
The Modbus register list is available at Datakom
technical support.
There is no termination resistor in the controller.
120 ohm termination resistors must be installed at
each end of the line.
