6: M
ODBUS
C
OMMUNICATION
6-22
FC6A S
ERIES
M
ICRO
S
MART
A
LL
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IN
-O
NE
T
YPE
C
OMMUNICATION
M
ANUAL
FC9Y-B1730
4.
Configure the requests of the Modbus TCP Client.
A maximum of 255 requests can be entered in one request table. Specify the Modbus TCP servers with the remote host numbers.
After all requests are configured, click
OK
button to close the dialog box.
Choose to use
Req. Execution Devices
and
Error Status
data registers if necessary. When using
Req. Execution Devices
and
Error Status
data registers, enter the first number of the devices.
5.
Download the user program to the FC6A Series MicroSmart.
Programming for the Modbus TCP client is complete. Details about parameters and valid values are as follows.
Function Code
The Modbus TCP of the FC6A Series MicroSmart supports eight function codes as listed in the table below. Supported function
codes and valid slave addresses vary with each Modbus server device to communicate with. Configure the function codes
according to the specifications of the Modbus server devices.
Function Code
Data Size
Slave Address
FC6A Series MicroSmart as Modbus Slave
01 Read Coil Status
1 to 128 bits
000001 - 065535
Reads bit device statuses of Q (output), R (shift register), or
M (internal relay).
02 Read Input Status
1 to 128 bits
100001 - 165535
Reads bit device statuses of I (input), T (timer contact), or C
(counter contact).
03 Read Holding Registers
1 to 64 words
400001 - 465535
Reads word device data of D (data register), T (timer preset
value), or C (counter preset value).
04 Read Input Registers
1 to 64 words
300001 - 365535
Reads word device data of T (timer current value) or C
(counter current value).
05 Force Single Coil
1 bit
000001 - 065535
Changes a bit device status of Q (output), R (shift register),
or M (internal relay).
06 Preset Single Register
1 word
400001 - 465535
Changes word device data of D (data register).
15 Force Multiple Coils
1 to 128 bits
000001 - 065535
Changes multiple bit device statuses of Q (output), R (shift
register), or M (internal relay).
16 Preset Multiple
Registers
1 to 64 words
400001 - 465535
Changes multiple word device data of D (data register).