Processing time of when multiple programs are executed with a MELSEC iQ-R series CPU module

When multiple programs are executed, the processing time (program switching time) becomes "Number of program files × 0.9 [us]". More Details >>

Remedies for WDT errors on a MELSECNET/H board

The error code indicates a WDT (watchdog timer) error. It is determined as the cause that the MELSECNET/H driver cannot work due to a computer or OS hang, or... More Details >>

HPR request flag

It depends on the setting of servo parameter "[PA03] Absolute position detection system" whether the HPR request flag ("[Md.31] Status": b3) turns ON or not.... More Details >>

I cannot place a main base unit in a module configuration diagram with GX Works3.

You may have already placed a main base unit in the module configuration diagram. Scroll up or down in the module configuration diagram and check if a main ... More Details >>

Changing the time of a programmable controller by using the clock data write instruction (TWR)

When changing the time by using the clock data write instruction (TWR), the control of M8015 (Clock stop/adjustment) is not required. * When the clock data... More Details >>

How to check devices assigned to labels of GX Works3

GX Works3 and the MELSEC iQ-R series do not use actual devices as automatic assignment devices of local labels. The local labels use "label areas" in the "d... More Details >>

PLC type change in GX Developer

Follow the steps below and then execute PLC type change.- On the menu of GX Developer, select [Online] -> [Monitor] -> [Stop Monitoring (All Windows)],... More Details >>

Parameter initialization

The following shows the initialization procedure. (1) Turn OFF the PLC ready flag. (2) Turn ON "[Cd.2] Parameter initialization request". [QD75M, QD75MH, LD... More Details >>

I cannot select [Transfer Setup] in GX Developer because it is displayed in gray.

You cannot select the item while the programmable controller is being monitored. Execute [Close all windows] of [Window] from the tool bar, and check if Tra... More Details >>

Minor error 197AH

Minor error 197AH (Home position return zero not passed) occurs in the following case:"[St.1066] zero pass" is OFF when the re-movement to the home position ... More Details >>