Siemens LMV3 series, Технические инструкции, Страница: 165 / 224

LMV Series Technical Instructions
Document No. LV3-1000
SCC Inc. Page 5 Section 7
Modbus functions
The following Modbus functions are supported:
Function number Function
0x03 / 0x04 Reading n words
0x06 Writing one word
0x10 Writing n words
Requirements for the Modbus master
A Modbus system whose connection is based on RS485 is a robust system.
With regards to the possible cable lengths and the loads produced by the various users and
environmental conditions, the master software should satisfy the following criteria:
•
In the case of write processes, correct writing must be checked through back-reading
•
In the case of read processes, it must be checked whether a reply from the slave is received. If
there is no such reply, the inquiry must be repeated, or it must be checked whether an error
occurred (wiring, valid Modbus address, etc.)
Modbus addresses
Overview table
Function Address
dec/hex
Number
of words Data designation Access Data
format Data type /
coding
Range
03/04 0/0h 1 Burner control phase R U16 0...255
03/04 1/1h 1 Position of current fuel actuator R S16 Degrees -50... 150°
03/04 4/4h 1 Position of air actuator R S16 Degrees -50... 150°
03/04 8/8h 1 Manipulated variable VSD R S16 Percent 0…100 %
03/04 9/9h 1 Current type of fuel
(default setting: 0) R U16 0= fuel 0
1= fuel 1 0...1
03/04 10/Ah 1 Current output R U16 Fire rate Modulating:
0…100%
Multistage:
1001…1003
Invalid:
32767
03/04 13/Dh 1 Flame signal R U16 Percent 0…100 %
03/04 14/0Eh 1 Current fuel throughput R U16 0..65535 0…6553.4
m
3
/h, L/h,
ft
3
/h, g/h
Error:
65535.5
03/04 21/15h 2 Startup counter total R S32 0…999999
03/04 25/19h 1 Current error: Error code R U16 0...255
03/04 26/1Ah 1 Current error: Diagnostic code R U16 0…255
03/04 27/1Bh 1 Current error: Error class R U16 0...6
03/04 28/1Ch 1 Current error: Error phase R U16 0...255