INM 725B Rev 21
95
13 .4 .13 Write Multiple Coils – Function 15 - Request
Register Address
This register is used to address the first coil to be written. If the port register offset has been
set then this would offset the default start register. To write the input status write to coils 0
-255 with coil 0 being channel 1 unless mapping has been enabled then this will be defined in
the mapping spreadsheet.
Quantity
This represents the number of coils the user wishes to write to
Byte Count
This represents the number of data bytes sent
Data
This represents the status of the coil to be written
0 = Input Normal
1 = Input Abnormal
13 .4 .14 Write Multiple Coils – Function 15 – Response
Register Address
Number of coils that have been written
Quantity
This represents the number of coils the user wishes to be written
Typical Example of Message Format
To write all the inputs abnormal on a 20 way annunciator at node 1 the user would need to send
the following message
RTU
ADDRESS
FUNCTION
REGISTER
ADDRESS
No. of
REGISTERS
BYTE
COUNT
DATA
DATA
DATA
ERROR
CHECK
01
0F
00 00
00 14
03
FF
FF
0F
61 B1
ASCII
:
ADDRESS
FUNCTION
REGISTER
ADDRESS
No. of
Registers
BYTE
COUNT
DATA
DATA
DATA
CR
LF
3A
30 31
30 46
30 30 30 30
30 30 31 34
30 33
46 46
46 46
30 46
0D
0A
