Siemens Milltronics BW500, Руководство по эксплуатации

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Communications
11.5 Modbus RTU/ASCII Protocol
BW500 and BW500/L
146
Operating Instructions, 12/2016, A5E33482052-AD
Parameter Values
Bit Mapped bits are packed into registers in groups of 16 bits (1 word). In this manual we
number the bits from 1 to 16, with bit 1 being the least significant bit and bit 16 referring to the
most significant bit.
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
MSB LSB
Large numbers are put into unsigned 32 bit integers with a fixed decimal place of three. For
example, a value of ‘7345’ represents a value in the BW500 ‘7.345’. The default word order is
that the first word is the most significant word (MSW) and the second word (register) is the least
significant word (LSW).
For example, if we read R41,431 as a 32-bit, the 32 bits would look like the following:
R41,431 R41,432
16 MSB 1 16 LSB 1
32 32-bit integer value (UNINT32) 1
The whole is read as a 32-bit integer. The most significant byte (MSB) and least significant byte
(LSB) can be reversed to accommodate some Modbus drivers.
Text Messages
If a Siemens Milltronics device parameter returns a text message, that message is converted to
a number and provided in the register. The numbers are shown in the table below:
Number Text Message as Displayed on LCD
22222 invalid value
30000 off
30001 on
30002 = = = =
30003 (parameter does not exist)
30004 err
30005 err1
30006 open
30007 shrt
30008 pass
30009 fail
30010 hold
30012 hi
30013 de
30014 en
-32768 value is less than -20,000
32767 value is greater than 20,000