Parker 8903/RS, Техническое руководство

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8903/RS RS485 Communications Interface
Address: Address identifier: 1 - 247
Baud Rate: Standard baud rates: 1.2k – 115.2k
Data Bits: 8 (fixed)
Parity: Even, Odd, None
Word Order: 32-bit word (register) order: Low Word First, High Word First
Timeout ms: Process active timeout in milliseconds: 0 – 60,000ms. Set to 0 to disable.
If used, the timeout should be set to greater than the maximum period in
which frames addressed to the node will be received. This depends on a
number of factors including the baud rate, quantity of data, number of slaves,
cycle time of the master, etc.
7.
If required, click on Save List to generate a text file mapping DSE registers to Modbus
registers.
Initial DSE Fieldbus Register Values
Modbus registers mapped to DSE registers will have initial values of zero. A DSE fieldbus
input register will generate an event in DSE the first time data is written to the Modbus register
mapped to it. Subsequent events will be generated when the data written to the register
changes .
DSE Input/Output Registers and Persistent Data
It is possible to have a DSE input register and a DSE output register map to the same Modbus
register(s). In this case both fieldbus connectors
must be the same DSE type, i.e. VALUE,
INTEGER or BOOLEAN.
A change of data on the DSE output connector will generate an event on the input connector.
Any limiting of data that occurs due to conversions will not appear on the input connector.
For example, consider a DSE INTEGER input connector and a DSE INTEGER output
connector mapped to the same modbus register with an RS485 data type of UINT16, as shown
below. If a data value of say 100,000 is send to the output connector, 100,000 will appear at the
input connector. However, the data on the RS485 bus will be limited to 65,536; the maximum
limit of UINT16.
An input and output connector mapped to the same Modbus register(s) may be used with a
persistent block as shown in the example below. This combination allows persistence of data
when the power is removed from the 890 drive.
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