4
MODBUS(R) STANDARD FUNCTIONS
4.14 Write Multiple Coils (FC: 15)
4 - 50
1
OVERVIEW
2
SYSTEM 
CONFIGURATION
3
SPECIFICATIONS
4
MODBUS(R) STANDARD 
FUNCTIONS
5
FUNCTION
6
PRE-OPERATIONAL 
PROCEDURES AND 
SETTINGS
7
PARAMETER SETTING
8
UTILITY PACKAGE 
(GX Configurator-MB)
4.14  Write Multiple Coils (FC: 15)
Writes values (ON/OFF) to multiple coils.
(1) Request message format (Master   Slave)
 * 1   The number of the specified write points must be matched with the number of bits specified as the 
number of bytes.
For example, when the write points are set to 16, set the number of bytes to 2 bytes (= 16 bits).
Figure 4.82 Write multiple coils (Request message)
Data
(L) (L)
.   .   .
b0b1b2b3b4b5b6b7
Function code
Function 
code 
(0F
H)
Head coil number 
(0000
H to FFFFH)
Write points*1 
(0001
H to 07B0H)
Number of 
bytes n*1 
(0001
H to 
00F6
H)
Device 
data 
1
Device 
data 
n
(Number of bytes n)
(Device data 1 to n )
Device data 1
Device data n
Data storage order
0 : OFF
1 : ON
The values (ON/OFF) stored into the device data 1 to n are written to 
the coils in order from low-order to high-order bits of the device data.
(H)
(H)