Panasonic FP0H User Manual page 56

MODBUS RTU
Master-Slave Communication
Code Description
SEND / RECV
①
executable flag
COM port No. of a master
②
unit
③
MODBUS command
MODBUS unit No. of a
④
destination unit
MODBUS address of a
⑤
destination unit
⑥
Number of receive data
Master unit memory area
⑦
to store receive data
(Note): For details of instruction programming, refer to 8.2.5 [F146 RECV] Data Reception (MODBUS Master:
Function Code Specification).
KEY POINTS
Other F145 (SEND) / F146 (RECV) instructions cannot be executed at the
•
same time to a communication port during master communication. Confirm
that the "SEND / RECV instruction executable flag" is ON, and execute the
instructions.
• F145 (SEND) / F146 (RECV) instruction cannot be executed at the same time
to a port during slave communication.
• The processing of F145 (SEND) / F146 (RECV) instruction is handled during
the execution of ED instruction. Check the SEND / RECV done flag to
confirm the completion of transmission / reception. Turned ON in the case
of an error, and an error code is stored in DT90123-DT90125.
• In the case of COM0 port, specify "HF" as a COM port No. for an operand of
the F145 (SEND) / F146 (RECV) instruction.
 Special relays / special data registers
SEND / RECV executable flag
SEND / RECV done flag
SEND / RECV done code
(Note): The Nos. in brackets indicate devices that are compatible with existing FP-X / FPΣ.
6-4
This is inserted to confirm that no SEND / RECV instruction is in progress for
the same port. Turns ON when an instruction is executable.
Specify a COM port No. for Bit 15 to Bit 12 of control data.
HF: COM0 port; H1: COM1 port; H2: COM2 port
Specify a MODBUS command for Bit 11 to Bit 8 of control data.
H1: Command 01 (Read coil state)
H2: Command 02 (Read input state)
H3: Command 03 (Read hold register)
H4: Command 04 (Read input register)
Specify a unit number of a destination unit for Bit 7 to Bit 0 of control data.
Range: H01 to HFF (K1 to K255)
Specify the MODBUS address of the memory area of a destination unit that
stores receive data.
In the case of bit data, the max. number is 2040 (07F8H).
In the case of word data, the max. number is 127 (7FH).
Specify the memory area of the master unit that stores receive data.
COM0
R9134
R9135
DT90123
COM1 COM2
R913C (R9044) R9144 (R904A)
R913D (R9045) R9145 (R904B)
DT90124 DT90125