Write data from the HMI to one or more devices, once and only at start-up

 

It may be useful to write to one or more devices (PLC, drive, sensors, etc.) only once and at HMI start-up

Parameters to backup

You can save the parameters to be backed up from the LB50000 bits register and LW50000 words registers of the HMI. See HMI register types

For example, create a “Numerical input” with address LW50000

From now on, the contained value of LW50000 will always be saved in the HMI, even after a power cut.

Note: If you wish to keep these data also after downlodin a new projet, check this in HMI parameters

Data Transfert at the HMI startup

Let’s assume that you want to write this LW50000 to a Modbus device only once and at HMI start-up

To do this, we’re going to perform a data transfer on a trigger. The trigger will be the LB60000 bit, which is a register that changes to 1 when the HMI starts up.

From now on, when the HMI starts, data transfer is executed at start-up.

You will find the value contained in LW50000 (HMI) in the 4×0 register of your device

Thereafter, this transfer is no longer executed.