Omron C200HW-CORT21, Руководство по эксплуатации

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Message communication
Section 4-1
40
4-1 Message communication
Three functions
The message communication is used for the following functions:
1. Reading the error log
2. Transmitting a user defined CAN message
3. Receiving a user defined CAN message
The error log stores the last 25 errors that have occurred due to message
communication. These errors can be read with the IORD instruction.
Function 2 and 3 enable to interface the C200HW-CORT21 with devices that
have implemented a specific protocol.
The next sections will first describe the general use of the IOWR / IORD
instructions and the error log. After that, the other two message
communication functions of the C200HW-CORT21 are explained in detail.
4-2 IOWR / IORD
The ladder symbols for IOWR and IORD are shown below.
IOWR (-) @IOWR (-)
C C
S S
D D
C Control code
value: The code for the respective function to execute (see below)
S First source word
value: The address of the first word of the PLC data area that
contains the message to be transferred to the Unit.
D Destination information
value: Combination of the Machine number of the Unit and the
message length (number of words in BCD).
Message length (001 ~ 128)
Machine number (0 ~ F)