MC43 ( MC4x ) RTC

Antonio Garcia 6 years ago updated by Gustav Widén (System support) 1 year ago 7


I've been reading instruction book, but I'm not sure about this doubt. And have no MC43 at the moment to be tested.

In IQAN Design, when adding an MC43 module to the system, it doesn't have "RTC Enabled" property in its property inspector. But, I doubt if it has no internal RTC, or it does, but can't be disabled.

Does MC43 have RTC?


In case MC43 does NOT have RTC:

Will event logs always register the time from system startup? 

If there's another master in the system with enabled RTC, MD4 for instance, will the MC43 Logs take the time from the MD4 for its event logs?



Ok! Thank you!

Satisfaction mark by Antonio Garcia 6 years ago

MC43 does not have a real-time clock. Logs will show startup count and time since last startup instead of date and time.

If there is a master with real-time clock, such as the MD4, the MC43 will get date and time from that master and use it when creating log records.


If we do not have an MD4 together with the MC43 but we do have an IQAN GT Modem, is it possible to get the date and time from that modem?

The MC4x will get time and date if a module on the bus sends the J1939 TDA message (Time/Date Adjust, PGN 54528) 

But the current software on the GT doesn't implement this. 


Has this changed with later GT software updates?

One thing that i have noticed is that the time can only advance.  I have tried sending a TDA message to an MD4-7/MC43 multimaster system and the new time and date would not be accepted if it was in the past with respect to the current time and date in the system.  Is this expected?

please help me understand the terminology when there are two master controller (md4x tag id 3 & mc4x tag id 0) in this case MC4X is the master controller so if the MD4X RTC pin is wired and protected can we still get the real time /log time on the mc43 since they are data link connected

or the IQAN MD4-5 display is no longer a master, so unsure if the circuit below is relevant anymore?

Image 3527

Both MD4 and MC4x are master modules, meaning they run application logic. 

The address 0 "headmaster" is the primary connection point for diagnostic tools and the module that handles gateways. 

This has no impact on the clock synchronization. 

Since the MD4 has an RTC, this is the module that can keep date and time information when the system is powered down. 

The clock is synchronized when master module comes online on the diagnostics bus. 

Say that you power up the MC4x first, and then the MD4 a minute later. 

The MC4x will then have to start without a date and time, and it will fall back to using number of startups and time since startup instead of date and time. 

When the MD4 powers up, it will automatically send its clock information on the diagnostics bus, and the MC4x will continue using that time.