Ladder Program Example - Omron CQM1H-SCB41 Operation Manual

Using Protocol Macros
5-7-3

Ladder Program Example

Connections
Send Word Allocation for Sequence No. 000 (Present Value Read)
First word of S Number of send data words
send data
S + 1 (Undefined)
Receive Word Allocation for Sequence No. 000 (Present Value Read)
Receive data D
Number of receive data words
storage words
D + 1 Present value
The following diagram shows an example in which sequence number 000
(Present Value Read) for a Temperature Controller (E5@K Read Protocol) is
executed using the protocol for an OMRON Temperature Controller connected
to port 2 (RS-422A/485) of a Serial Communications Board.
Serial Communications Board
RS-422A/485
Send data
Receive data
Temperature
Controller E5@K
Unit No. 00
Word
Unit No. S
S + 1
Word
D
D + 1
32 Units max.
Specifies the Temperature Controller Unit No. ,
Port 2
sends the PRESENT VALUE READ command
send data, and receives the present value set
in the response in the specified word.
Temperature
Controller E5@K
Unit No. 01
31 Units max. for 2-wire connection
32 Units max. for 4-wire connection
Contents (data format)
Number of send data words
(4-digit BCD)
Unit No.
(2-digit BCD)
Contents (data format)
Number of receive data words
(4-digit BCD)
Present value
(4-digit BCD)
Section 5-7
Temperature
Controller E5@K
Unit No. 31
Data
0002 (fixed)
00 to 31
Data
0002
Scaling
Lower limit to upper limit
87