Dyacon LD-1, Руководство пользователя

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DYACON LD-1 Manual Modbus
5.0 Modbus
5.1 Modbus Summary
Modbus is a simple protocol that can be transmitted over several modes including TCP/IP, TIA-
232-A (RS-232), TIA-485-A (RS-485), TCP/IP, SMS, and many others.
Dyacon LD-1 uses Modbus-RTU over RS-485.
LD-1 is a slave device and must be connected to a host device, such as a programmable logic
controller (PLC), host computer with an RS-485 adapter and Modbus software, or to the Dyacon
weather station control module.
RS-485 is a robust, differential pair electrical protocol that is noise immune and capable of long
cable runs. With twisted pair cabling, such as CAT-5, distances over 1200 m (4,000 ft) can be
achieved. LD-1 can be configured for low bit rates to extend the range. Relatively long runs are
achievable even without twisted pair cables.
The wide operating voltage range and low power of LD-1 allows for power to be injected over
the same data cable without concern for excess voltage drop. (Two wires for power and two for
data.)
For example, 1200 m (4000 ft) of Cat-5 cable (24 AWG) will result in a voltage drop of less than
0.2 V at an operating current of 2 mA.
LD-1 ships standard with 2 m (6.5 ft) of cable.
5.2 Modbus Utilities
The address of the sensor and other parameters are configurable. A Modbus computer utility may
be required to change these settings. A number of utilities are available including:
ModBusConstructor by KurySoft ( www.kurysoft.com )
Simply Modbus ( www.simplymodbus.ca )
ModbusTools ( www.modbustools.com )
Only ModBus Constructor and the companion Modbus Reader have been tested with the
Dyacon product.
A list of Modbus software can be found at: www.modbus.org/tech.php
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