When The Pulses Are Not Measured Correctly; When The Pwm Output Is Not Correct; When The Inter-Module Synchronization Function Does Not Operate Correctly - Mitsubishi Electric RD62P2E Application User's Manual

When the pulses are not measured correctly

Check item
Check whether the shielded twisted pair cables are used for pulse input
wiring.
Check whether any noise comes from the grounded part of the high-speed
counter module.
Check whether measures against noise are taken for the adjacent devices
and inside the control panel.
Check whether the distance between the high voltage device and pulse input
line is kept enough.
Check whether the section of the pulse to be measured is corresponding to
the pulse measurement section setting
Check whether the program, if used for reading out the measured pulse value,
reads out the value in unit of 2 words (32 bits).
Check whether the external wiring of the pulse measurement terminal is
normal.

When the PWM output is not correct

Check item
Check whether the CPU module indicates any error.
Check whether the counter operation mode is set to PWM output mode.
Check whether a voltage is applied to the power supply terminal for external
output.
Check whether the external wiring of the PWM output point No.1 terminal
(EQU1) and PWM output point No.2 terminal (EQU2) is normal.
Check whether anything other than a resistive load is connected to the PWM
output point No.1 terminal (EQU1) and PWM output point No.2 terminal
(EQU2).
Check whether the shielded twisted pair cables are used for PWM output
wiring.
Check whether any noise comes from the grounded part of the high-speed
counter module.
Check whether measures against noise are taken for the adjacent devices
and inside the control panel.
Check whether the distance between the high voltage device and PWM output
line is kept enough.
When the inter-module synchronization function does not
operate correctly
Check item
Check whether the high-speed counter module is set as the synchronization
target module in the system parameter setting of GX Works3.
Check that the CPU module is in the RUN status.
Check whether the inter-module synchronous interrupt program exists.
Check whether the EI instruction is executed.
3 TROUBLESHOOTING
50
3.3 Troubleshooting by Symptom
Action
Use the shielded twisted pair cables for pulse input wiring.
Separate the grounding cable of the high-speed counter module from the
grounded part. If the high-speed counter module touches the grounded part,
separate it.
Take noise reduction measures such as attaching a CR surge suppressor to
the magnet switch.
Bundle the pulse input lines separately from other lines in piping and tubing,
and keep a distance of 150mm or more between the pulse input lines and the
power line even inside the control panel.
Correct the pulse measurement section setting to suit the section of the pulse
to be measured.
Read out it in unit of 2 words (32 bits).
Check the external wiring to correct the errors.
Action
If the CPU module indicates an error, refer to the troubleshooting in the
following manual.
 MELSEC iQ-R CPU Module User's Manual (Application)
Set the counter operation mode to PWM output mode in Basic setting.
Apply a voltage to the power supply terminal for external output.
Check the external wiring to correct the errors.
Connect a resistive load because the output waveform is highly distorted by
connecting a load other than a resistive load.
Use the shielded twisted pair cables for PWM output wiring.
Separate the grounding cable of the high-speed counter module from the
grounded part. If the high-speed counter module touches the grounded part,
separate it.
Take noise reduction measures such as attaching a CR surge suppressor to
the magnet switch.
Bundle the PWM output lines separately from other lines in piping and tubing,
and keep a distance of 150mm or more between the PWM output lines and
the power line even inside the control panel.
Action
Check "Module Synchronous Status" on the system monitor of GX Works3.
When "Module Synchronous Status" is displayed as "-", the high-speed
counter module is not set as the synchronization target module.
Set the high-speed counter module as the synchronization target module in
the system parameter setting of GX Works3.
If the CPU module is not in the RUN status, switch the status to RUN.
If the inter-module synchronous interrupt program does not exist, add the
program.
Execute the EI instruction.