AIO module startup fault

[cnt]

Hello,
I have RevPi Core3 with DIO and AIO modules.
During completion of our project, the problem with AIO module start-up appeared.
After power-on (after long period in the off state) the module stays in the phase when red power LED is blinking and is not detected by the Core unit.
Software reboot of the core does not help.
After powecycling the 24V/45W supply the module works normally.

The configuration and firmware version of the modules:

Code: Select all

Address: 0 module type: 95 (0x5f) RevPi Core V1.2
Module is present
     input offset: 202 length: 6
    output offset: 208 length: 5

Address: 31 module type: 96 (0x60) RevPi DIO V1.4
Module is present
     input offset: 89 length: 70
    output offset: 159 length: 18

Address: 30 module type: 103 (0x67) RevPi AIO V1.3
Module is present
     input offset: 0 length: 20
    output offset: 20 length: 4

Address: 64 module type: 24580 (0x6004) ModbusRTU Master Adapter V0.0
Module is present
     input offset: 213 length: 101
    output offset: 314 length: 75

I'll be glad for any idea or help.

[dirk]

Hi this problem arises often in case of power cycle. Some power supplies have a too long ramp up delay until the 24Volts.
Try to change the power supply with i.e. one from our online shop.
A qorkaround is to change the position of the devices so that the AIO is at the end of the PiBridge. I.e. [AIO] - [DIO] - [RevPi].

[cnt]

I have tested the MeanWell power supply MDR 40-24 and it looks the startup process works as it should.
The old power supply, which did not work, was made by the same manufacturer, but it was the medical safety version RPS 45-24. It has even 5W more power than the MDR version and in the catalogue it has the same startup time. Strange.
However, thank You for the hint with the supply, I didn't suspect it, other electronics works fine, and power was at about 20W.
Tomas

[dirk]

Hi Thomas, thank you for positive reply to this topic. Maybe you could share more information about the power supply which did not work on your setup.

[cnt]

I've had some time this week so i measured startup times of power supplies (MeanWell RPS-45-24 and MDR-40-24) i used. There is a difference of about 0.12s in the startup time and the voltage waveform is definitely different - see the attached image.
I hope it will help You to improve the AIO power supply tolerance to various power condition.
Tomas

[dirk]

Hi Tomas, thank you for your feedback. I'll take this to our development team for discussion.

[dirk]

Hi Thomas, so here for reference the Meanwell power supply form our online shop needs 30-35 ms for ramp up to 24V. This works.