3 when communication fails, Modbus – IAI America ROBO Cylinder Series User Manual
Page 314

7. T
roubleshooting
306
Modbus
7.3 When Communication Fails
Select an applicable item and perform the processing enclosed with .
The specific processing details are explained after the flowchart; check the details indicated by the *
symbol.
{
= Yes, X = No
Symptom: Cannot communicate normally!
Was communication possible until now?
Continue to the next page
Cannot communicate with all controllers?
Cannot communicate with any controllers. o
Cannot communicate with specific controllers. o
(1) Host failure o Repair host
(2) Disconnection of communication cables
or poor contact due to vibration and
similar o Fix disconnection
(1) Controller failure o Replace the controller
(2) Disconnection of communication cables between
controllers and junctions o Fix disconnection
(3) Dislocation of terminating resistor o Fix dislocation
(4) Wrong controller axis number setting (when
controllers are replaced, parameters are initialized,
the version is upgraded, etc.) o Check *4
(5) Wrong controller communication speed setting (when
controllers are replaced, parameters are initialized,
the version is upgraded, etc.) o Check *6
(6) Wrong transmitter activation time setting (when
controllers are replaced, parameters are initialized,
the version is upgraded, etc.)
o
Check parameter No. 17
Can any of the parts of the communication cables be moved?
There are movable parts o Disconnection of communication cables o Fix disconnection
Is the power supply voltage to each device normal? (each RC controller, SIO converter, etc.)
Power supply voltage error o Set normal power supply voltage
Did the failure occur after the surrounding environment was changed? (Peripheral devices, etc. have been changed.)
Occurred after change o Malfunction due to noise
o
(1) Decrease the communication speedo Check *2
(2) Change communication cable wiringo Check *7
(3) Check connection of FG of each RC controller *7
(4) Mount a clamp filter on the power lines
(5) Check grounding of the control board *7