Iai-america XSEL Ethernet Manuel d'utilisateur télécharger pdf (Page 24)

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4.4 Correspondence of Modbus/TCP Address and X-SEL I/O

Modbus/TCP can address the same object using either bit addressing or word addressing.

The DI area (bit numbers from No. 0 up to No. 299 can be defined) of the X-SEL controller is mapped

in the word address 0x400 (1024) (coil and holding register as viewed from the PC side) under

Modbus/TCP.

The DO area (bit numbers from No. 300 up to No. 599 can be defined) of the X-SEL controller is

mapped in the word address 0x000 (0) (input discrete and input register as viewed from the PC side)

under Modbus/TCP.

Since the DI addressing in the X-SEL controller and the addressing via Modbus are different, it is

important to note the following two points:

1. The number order of one byte in the byte boundary is reversed.

(Example)

X-SEL DI7  Modbus bit address 1 (Modbus/TCP bit address 0)

DI0  Modbus bit address 8 (Modbus/TCP bit address 7)

2. When register access is executed from the X-SEL controller using an IN, INB, OUT or OUTB

command, the upper and lower bytes will be reversed.

(Example)

Writing 0x1234 to 16 bits from X-SEL DO300

 Modbus input register 0 (Modbus/TCP bit address 0)

DI0  Modbus bit address 8 (Modbus/TCP bit address 7)

Both the Motorola and Intel formats can be supported using an FMIO command. (Refer to Chapter 2,

“Explanation of Commands,” in the operation manual for the X-SEL controller.) The FMIO command

changes the endian in IN/OUT commands. Executing input or output after an FMIO command

execution with the format type set to “1” will align the byte order with Modbus/TCP. Each FMIO

command is valid only with respect to the task for which the command is executed.

A table of correspondence is shown on the next page.

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 59 60

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Iai-america XSEL Ethernet Manuel d'utilisateur Page 24