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TB284 Rev1 PLC Communication Fault
The most common cause of this error is that the fiber optic cables are not plugged in
correctly to the MPU11 and GPIO4D* Confirm that the fiber plugged into the gray fiber optic
xmitter labeled �1� on the MPU11 is connected to the blue receiver labeled �1� on the
GPIO4D and that the fiber optic cable plugged into the blue fiber optic receiver labeled �3�
on the MPU11 is connected to the gray xmitter labeled �3� on the GPIO4D
*For ALLIN1DC systems with this error it is likely a problem with the ALLIN1DC Please
contact your dealer to arrange repair replacement or further troubleshooting
1 Does the GPIO4D have power? Check the 3 3 5v 12V and 12V LED's if not lit check
for 5V 12V and 12V input on H6 If voltage is present but the corresponding LED or
the 3 3V LED is not lit send the GPIO4D in for repair If no voltage is present check AC
supply 85 264VAC to the GPIO4D power supply If AC supply voltage is present but any or
all of the 5V 12V or 12V signals are missing it's likely a problem with the GPIO4D power
supply Please contact your dealer to arrange repair replacement or further troubleshooting
2 Did the LED's on the Jog Panel/Pendant flash on power up? If the LED's did not flash
immediately on power up check the back of the jog board and confirm that the data cable is
correctly plugged into the header labeled CPU10 If this cable is plugged in correctly and the
LED's did not flash on power up it is likely that the Jog Panel/Pendant will need to be returned
for repair Please contact your dealer to arrange repair replacement or further troubleshooting
3 Are the fiber optic cables transmitting and receiving signals correctly? The Fiber optic
cables plugged into the blue fiber optic receivers on both the MPU11 and GPIO4D should have
a �bright� red light visible at the end of the fiber if you unplug the fiber optic cable from the blue
receiver and look at the end of it While �bright� is a relative term if there is any doubt about
whether the signal is �bright� or not there is almost certainly a problem Confirm that the
transmission media the clear portion of the fiber optic cable is flush with the plug on the end
While watching the signal manipulate and flex the cable and observe that the signal doesn't
dim or blink while the cable is moved Now do the same thing at the receiver at the MPU11 If
the signal dims or blinks it indicates that the fiber optic cable is cracked and the cable will
need to be replaced If there is no signal at all pull the fiber out of the transmitter gray
receptacle on the other end and look into the transmitter if there is a signal coming out of the
transmitter the the fiber optic cable will need to be replaced if there is no signal coming out of
the transmitter the board with the transmitter will need to be replaced Please contact your
dealer to arrange repair replacement or further troubleshooting
4 Is the �PLC Ok� LED on? If the �PLC Ok� LED is off there is a problem with either the
MPU11 or GPIO4D board Please contact your dealer to arrange repair replacement or further
troubleshooting
5 Does your MPU11 have the updated crystal installed? MPU11 boards that shipped prior
to ##### may need to have the crystal replaced due to a manufacturing defect in the crystal If
your MPU11 is dated prior to ##### see pic return it for repair Please contact your dealer to
arrange repair or replacement