Do the M172* PLCs have data stored on board that can be used to identify the PLC in the event of a recall?

[obscuresc]

There was a batch of PLCs that we handled a while ago that caused an display flicker issue. The advice at the time was to refer to the serial number of the PLC, located on the box or on the sticker.

As far as I know, the PLC does not have the serial number stored onboard the PLC. Is this still true? If so, is there any other data that could be used to identify the PLC for recall? 

Thanks.

[M_Cervati · Accepted solution]

Hello,

there isn't a serial number stored into  the PLC to identify the production batch, except in the label of the BOX. 

We can do a proposal to the BOC team in order to add this info into the PLC.

Best regards

Marco Cervati

[M_Cervati]

Sorry I specify better my reply.

There is the serial number also in the label (on the sticker) outside the plastic cover of the controller,

but the one in the carton box it is indicated also the code of fuctional test station.

BR

Marco

[obscuresc]

Hi Marco,

It would be great if the serial can be stored in the PLC! Looking forward to hearing more.

Regarding the serial numbers stored on the labels; they can also be useful for field technicians, but having a QR code or similar would be helpful for our factory processes.

Thanks!

[M_Cervati]

Hi,

I forward your request to the offer manager and BOC team to evaluate their realization.

Best regards

Marco Cervati

[ismailozinan]

Hi,

The serial number is not stored in a specific register, as Marco explained. However, in my own application, I base it on the MAC address. By using ST code, I write a number derived from the MAC address into an EEPROM location. This way, even if the EEPROM register is reset, the MAC-based number is still available.

In most cases, machine manufacturers also write the serial number assigned to the machine into the EEPROM. The ESME HVAC software and TM172P... already provide its own firmware version, and displaying this version on the screen is useful for determining which software will be used for future interventions.

Of course, these are only my personal views, there are certainly many other good solutions available. The best approach should always be determined jointly by the manufacturer, the end user, and the programmer, based on experience and requirements.

[obscuresc]

@M_Cervati thanks for passing my request on. Do you know if, at the PLC factory, the production line has the MAC address stored alongside the serial number? In this way, we could log the MAC addresses for recall purposes until the serial number feature is created.

@ismailozinan I'm looking at the serial numbers of the PLC itself, not that of our machine we fit it to. I do like your MAC address derived solution for creating our own serial number for our machine. It would be nice if EEPROM registers could be set explicitly to read only to prevent accidental modification. 

[FedericoM]

MAC address registers are readonly.

If you want a trick to make an EEprom readonly you have to do this:

- at boot copy the eeprom value EE_A into a global variable A

- in the background task copy back the value of A into EE_A using syswritepar<type>(ADR(EE_A),A)

Clearly you have to disable this process with some password in case you need to update EE_A