Plc Link Troubleshooting - Omron FH series User Manual

Note
Saving All of the Measurement Results
If you output data from more than one Data Output Unit or for repeatedly measured output data (e.g., for continuous
measurements), the same Data Output Area will be overwritten.
If you want to save all output data, use one of the following methods.
Method
Offset (PLC Link Com-
munications Only)
Controlling Data Out-
put with Handshaking
You can compare the received number of output data and the number of measurements for continuous measurements to
check if all of the measurement results have been received.
Use the following method to check the number of measurements that was actually executed.
• Application Example
Set a calculation to count the number of measurements that are executed in the measurement flow.
If you set something like [DO+1], each time a measurement is executed (each time the measurement flow is executed),
1 will be added to DO, so the present value of DO will give you the actual number of measurements.

PLC Link Troubleshooting

Cannot Input to the Sensor Controller (RS-232C/422 Only)
Problem
No response is received
after sending communica-
tions commands.
Responses are no longer
received after sending
communications com-
mands (but communica-
tions were working
previously).
No Data Is Output from the Sensor Controller
Problem
The GATE signal does not
turn ON.
210
Communicating with PLC Link
When using more than one Output Unit, you can offset the write destination of the output data for
each Output Unit.
Set the [Offset] for the Data Output processing item.
Reference: Output Format (Data Output) (p.188)
This function is enabled when you are performing data output from more than one Data Output
Unit.
Handshaking lets you control data output by using the GATE signal turning ON as a trigger for the
data output timing and by turning ON the DSA signal to read the output data. Each time that data is
output (from the second output on), read the output data and move it to a different part of I/O mem-
ory in the PLC.
Reference: Data Output Control with Handshaking (p.32)
Cause
There is a problem with the wiring.
There is a problem with the RS-232C set-
tings.
You are attempting to send commands while
the BUSY signal is still ON.
A cable has been disconnected.
A connector has been disconnected.
Cause
Handshaking is disabled. The GATE signal is
not output when there is no handshaking for
the PLC Link protocol.
The DSA signal is not ON (when handshak-
ing is enabled).
Description
Check the wiring. Check the cable connec-
tions.
Make sure that the settings are correct.
Send commands only when the BUSY signal
is OFF.
Check the cable connections.
Check the connector connections.
Enable handshaking for the output control in
the communications settings.
Turn ON the DSA signal from the PLC.
Vision System FH/FZ5 Series User's Manual
for Communications Settings (Z342)
Action
Action