Omron E5AN Communications Manual page 128

Appendix
Item
The host device is detecting the absence
of a response as an error before it
receives the response from the Control-
ler.
The host device is detecting the absence
of a response as an error after broadcast-
ing a command or sending a software
reset command (except for SYSWAY).
The host device sent another command
before receiving a response from the
Controller.
The host device sent the next command
too soon after receiving a response from
the Controller.
The communications line became unsta-
ble when the Controller's power was
turned ON or interrupted, and the host
device read the unstable status as data.
The communications data was corrupted
by noise from the environment.
A-4
Confirmation
Shorten the send data wait time in the Controller or increase
the response wait time in the host device.
The Controller does not return responses for broadcast or
software reset commands.
Always read the response after sending a command (except
for broadcast or software reset commands).
Wait for at least 2 ms after receiving a response before send-
ing the next command.
Initialize the reception buffer in the host device before send-
ing the first command and after turning OFF the power to the
Controller.
Try using a slower baud rate.
Separate the communications cable from the source of noise.
Use a shielded, twisted-pair cable for the communications
cable.
Use as short a communications cable as possible and no not
lay or loop extra cable.
Do not run the communications cable parallel to a power line
to prevent inductive noise.
If noise countermeasures are difficult to implement, use an
Optical Interface.
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