6. Function blocks
6.1 Manufacturer function blocks
Function code
Modbus
Modbus
reg.#
Operand Description Remark
0x06
(Write Single Register,
FC6)

0x10
(Write Multiple
Register, FC16)


0x17
(Write Multiple
Registers, FC23)
5000

RTC (second)
RTC Format
5000:
Second;
5002:
Minute;
5004: Hour;
5006: Day
in the
month;
5008:
Month;
5009: Year;
…
…
…
5009

RTC (year)













5006  Minutes, seconds
GALILEO
format High
byte, low
byte

5007  –
Hours
5008  Month
Day
5009  Year

7001
MW1
Marker word 1



…
…
…
7512
MW512
Marker word 512

8001
NW1
loc. NET marker
word 1
Only the
local NET
marker
words can
be written
to (marker
words for
other mod-
ules cannot
be written
to) 
…  …
8032
NW32
loc. NET marker
word 32
If a function code is used on Modbus registers that are not listed (gray), a value of 0 or an exception code will be
returned.
Please note that little-endian is used when converting bytes to words in
an easyE4. If you want to implement Modbus communications with big-
endian, you will need to make the necessary adjustments.
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