KROHNE ALTOSONIC V12 EN - Manual (Page 119)

MODBUS PROTOCOL DESCRIPTION AND SET-UP
10
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ALTOSONIC V12
www.krohne.com 04/2013 - 4002643502 - MA ALTOSONIC V12 R02 en
All sub-functions are supported.
10.5.8 Function 15: WRITE MULTIPLE COILS
Function 15 writes the status of 1...2000 contiguous logical (Boolean or ON/OFF) variables.
This function is not used, as in this application Boolean variables are not used as individual
entities. Boolean variables are represented by means of specific bits packed in 32 bit data word
(type “Long”).
10.5.9 Function 16: WRITE MULTIPLE HOLDING REGISTERS
Function 16 writes the contents of 1 to 123 contiguous holding registers in the slave.
When the address is a broadcast, the function pre-sets the same register references in all
attached slaves.
Request
The request message specifies the register references to be pre-set. Registers are addressed
starting at zero (register 1 is addressed as 0).
Example
An example of a request for slave device 17 to pre-set two registers starting at 40002 (decimal),
9C42 (hexadecimal) to 00 0A end 01 02 hex:
Response
The normal response returns the slave address, the function code, starting address, and
quantity of registers pre-set:
Header Slave address Function Sub-function Data Hi+Lo Error check Trailer
-- 11(h) 08(h) 00 00(h) A1B8(h) -- --
Table 10-6: Diagnostics
Heade
r Slave
addres
s Funct. Starting
address
Quantity Byte
counts Data Error
check
/
Trailer
- 11(h) 10(h) Hi
9C(h)
Low
41(h)
Hi
00(h)
Low
02(h)
04(h) Hi
00(h)
Low
0A(h)
Hi
01(h)
Low
02(h)
- / -
Table 10-7: Example multiple holding registers