Troubleshooting
4-32
Part 1105779-04
E 2014 Nordson Corporation
Photoeye, Encoder, and Interlock Troubleshooting
Use the I/O board LEDs and the relay LEDs in the master console to
troubleshoot problems with the photoeye, encoder, interlock, and alarm
circuits.
Table 4-12 Photoeye, Encoder, and Interlock Troubleshooting
Inputs
I/O Board
Terminals
Troubleshooting
Zone Photoeyes 1 − 8 Photoeyes are set for breaklight. When a part passes in front of the
zone photoeyes, the LEDs for the zone photoeyes should light. If
they do not, check the photoeye wiring and photoeyes.
Flag Photoeyes or
scanners or Inputs
from customer
Part ID system
9 −16 Photoeyes and scanners are set for breaklight. When a flag passes
in front of the photoeyes, the LEDs for those photoeyes blocked by
the flag, or the LEDs receiving a signal from the customer part ID
system should light. If they do not check the wiring and photoeyes
or customer part ID system.
Encoder 20 The LED should flash at the same rate as the encoder signal. If it is
not flashing when the conveyor is moving check the encoder wiring
and encoder.
Conveyor
Interlock
24 The LED should light as long as the conveyor is on or the keyswitch
is in the bypass position. If it is not on check the conveyor interlock
wiring. Without this signal the spray guns will not be triggered.
Relays (DIN rail) − The conveyor interlock relay LED lights when the conveyor is
running. The remote lockout relay LED is lit as long as it is
receiving a signal (lockout on). The alarm relay LED stays lit until
an alarm occurs, then goes out.
All 1−24 Input LEDs should indicate as described above. If none of the LEDs
will turn on, then check the following screens:
Zone and Part ID Inputs: Open the Input Status screen. Inputs
should display as lighted indicators.
Encoder: On the Main screen, if the encoder is providing a signal
then the conveyor speed should be greater than zero.
Conveyor Input: On the Main screen, if the conveyor is running
then the conveyor indicator should be green.
If the input indicators on the Main and Input Status screens are lit
but the I/O board LEDs are not, then:
Check the dipswitch and jumper settings on the PC104 I/O board
(see Figure 7-4 for the settings). If settings are correct, replace the
PC104 I/O board, ribbon cable, and I/O board. A new cable is
shipped with the I/O board.
WARNING: Always turn console power off before changing jumper
and dipswitch settings on circuit boards. If ribbon cable is not keyed,
make sure the colored trace in the ribbon cable is aligned with pin 1
at both connectors.
If the conveyor interlock LED (24) on the I/O board is operating
correctly and all or some of LEDs 1−20 are responding erratically,
then check the I/O board inputs common voltage. For sinking
inputs, +24 Vdc is applied to all HI terminals on the board as inputs
common.
To Next Page
Loading...
