Modbus Master - Function Codes - YASKAWA CP 341 Manual

Communication protocols
Modbus > Modbus Master - Function codes

6.4.4 Modbus Master - Function codes

Naming convention
Modbus Function codes
FC Function
01 Read coil status
02 Read input status
03 Read holding registers
04 Read input registers
05 Force single coil
06 Preset single register
07 Read exception status
08 Loop back test
11 Fetch communication event counter
12 Fetch communication event log
15 Force multiple coils
16 Preset multiple registers
58
Modbus has some naming conventions:
n Modbus differentiates between bit and word access; Bits = "Coils" and Words = "Reg-
ister".
n Bit inputs are referred to as "Input-Status" and Bit outputs as "Coil-Status".
n Word inputs are referred to as "Input-Register" and Word outputs as "Holding-Reg-
ister".
The following function codes are supported by the driver:
Action in the PLC
read in bits
read in bits
read in bits (16bit grid)
read in bits (16bit grid)
read in bits
read in bits
read in words
read in words
write in bits
write in bits
write in words
read in bits
-
read status word and event counter
read additional status
write in bits (1...2040bits)
write in bits (1...2040bits)
write in words (1...127 Register)
VIPA System 300S
memory bits M
outputs Q
timer T
counter C
memory bits M
inputs I
data block DB
data block DB
memory bits M
outputs Q
event
-
status, event
status, event, mes-
sage
memory bits M
outputs Q
data block DB
HB130 | CP | 341-1CH01 | en | 18-40