Omron SYSMAC FH Series User Manual page 190

2 Methods for Connecting and Communicating with External Devices
Command/
response method
Data output
after
measurements
*1 : You can use output controls (handshaking) to prevent output data from being externally output from the
communications buffer until the Controller (master) turns ON the Result Set Request (DSA) signal to
request the output data.
*2 : The following processing items ara used to read characters:
Character inspection, Barcode, 2Dcode, and OCR
*3 : For details of the Output Units outputting measurement data, refer to Settings Required for Data Output
on page 1 - 21.
Additional Information
The PLC Link protocol communicates using three link areas: Command Area, Response Area,
and Data Output Area. It is different from the serial PLC Link protocol used to inter-connect OM-
RON PLCs serially.
Precautions for Correct Use
In the default settings for PLC Link communications, the data output processing method is set
to the same processing used for models prior to the FZ4.
This setting synchronizes the measurement processing and data output processing so that all
data output processing finishes when measurement finishes. However, this makes the overall
processing time for the measurement flow longer.
If required for your application, change the communications settings to Asynchronous Output
mode, which performs measurement processing and data output processing in parallel.
For details, refer to Asynchronous Output on page 2 - 152.
2 - 128
PLC (master)
1. Command Area
You write the following control
commands for the Vision Sensor.
• Control signals
• Command code
• Command parameters
2. Response Area
The Vision Sensor writes the
execution results to the PLC.
3. Data Output Area
The Vision Sensor writes the output
data to the PLC.
FH/FHV Series Vision System User's manual for Communication Settings (Z342-E1)
Sensor Controller (slave)
Commands
The control commands that are
written to the Command Area are
executed.
Executi o n
Measurement results are written
Responses
to the Response Area of the PLC.
• Status signals
• Command code
• Response code
• Response data
• Measurement Flow
Read characters
Execution of
are written to the
processing item (1)
Output Area.
External
Data is written to the
Communications
outputs *1
Module.
Execution of processing
Communi-
*2
item to read character data
cations
Module
Execution of processing
*3
item for the Output Unit.
The Vision Sensor writes the values
measured by processing item (1).
...
Responds when a
command is received.
... Operations are
performed by
executing the
measurement flow.