Mitsubishi Electric MELSEC FX-2DA User Manual page 11

6
6.1 Preliminary checks
1. Check whether the output wiring and/or expansion cables are properly connected on FX-2DA analog special
function block.
2. Check that the FX system configuration rules have not been broken, i.e. the number of blocks does not
exceed 8 and the total system I/O is equal or less than 256 I/O.
3. Ensure that the correct operating range has been selected for the application.
4. Check that the MODE switch on the FX-2DA panel is set to the READY position.
5. Check that there is no power overload on either the 5V or 24V power source, remember the loading on
the FX base unit or a powered extension unit varies according to the number of extension blocks or
special function blocks connected.
6. Pit the main processing unit into RUN.
6.2 Error checking
If the FX-2DA special function block does not seem to operate normally, check the following items.
Check the status of the POWER LED.
Lit. : The extension cable is properly connected.
Otherwise : Check the connection of the extension cable.
Check the external wiring.
Check the status of"24V" LED (top right cover of the FX-2DA).
Lit. : FX-2DA is OK, 24V DC power source is OK.
Otherwise : Possible 24V DC power failure, if OK then possible FX-2DA failure.
Check the status of th "D/A" LED (top right cover of the FX-2DA)
Lit. : D/A conversion is proceeding normally
Otherwise : Check buffer memory #29 (error status). If any bits (b2 and b3) are ON, then this is why the D/A LED
is OFF.
DIAGNOSTICS