Saia-Burgess Controls AG
Bahnhofstrasse 18 I CH-3280 Murten I Schweiz
T +41 26 / 672 72 72 I F +41 26 / 672 74 99
www.sbc-support.com
Technical data Modbus
Bus system
Modbus, RTU according to IDA specification
Transmission rate
1200-2400-4800-9600-19 200-38 400-57 600-115 200.
The transmission Baud rate is automatically detected
Transmission mode
Even parity: 8 data bits, 1 stop bit
Odd parity: 8 data bits, 1 stop bit
No parity: 8 data bits, 2 stop bits
Bus length (max.)
1200 m (without repeater)
Response time:
Write: 60 ms
Read: 60 ms
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The Interface works only if the phase 1 is connected.
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The communication is ready 30s after the power on
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The use of energy meter in Bus with intensive communication could reduce the performance of the Bus
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Refresh time for the data is 10 s. For this reason one energy meter should be not polled faster as 10s.
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247 devices could be connected to the Modbus. Over 128 devices, a repeater should be used.
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The interface don’t have a terminal resistor, this should be provided external.
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For a description of the used registers please look at the register page
Data transmission
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Only «Read Holding Registers [03]/ Write Multiple Registers [16]» instructions are recognized.
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Up to 20 Registers can be read at a time.
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The device supports broadcast messages.
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In accordance with the Modbus protocol, a register R is numbered as R - 1 when transmitted.
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The device has a voltage monitoring system. In case of voltage loss, registers are stored in EEPROM (transmission rate, etc.)
Exception Responses
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ILLEGAL FUNCTION [01]: The function code is not supported.
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ILLEGAL DATA ADDRESS [02]: The address of some requested registers is out of range
or more than 20 registers have been requested.
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ILLEGAL DATA VALUE [03]: The value in the data field is invalid for the referenced register.
Change the Modbus address direct on device
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To modify the Modbus address, press 3 s on
►
touch
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In menu,
▼
increase address by 10,
►
increase by 1
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Once the address is selected wait for the root menu to come back
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