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We noticed that when we power up RevPI [Compact], all 8 DIGITAL OUT pins switch to HI for a brief period, perhaps 5-10[ms]. This happens during every boot. What can I do?

yes, this is unfortunately a known issue.
We are currently working on this bug.

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Would it be possible to switch off the watchdog timer for the digital outputs of the RevPi Compact Module?

• Unfortunately, it is impossible to deactivate the watchdog without hardware modifications.

The digital outputs of the RevPi Compact Module cause a peak when switching on, what can I do?

What was the solution?

• There is a workaround that fixes this behaviour on reboot, see here:

• (665) Digital Out Pins briefly switch to HI when booting - The Industrial Raspberry Pi Forum (revolutionpi.com)

What is the XXX chip used to multiplex analogue to digital conversions (item 2)?

I have found the following from various specs, etc:

1. DAC is a Dual channel DAC082S085 chip connected to SPI0 of the Raspberry Pi

2. ADC is multiplexed from an XXX chip (I assume on SPI1)

3. Digital I/O is via the GPIO pins (GPIO00 - GPIO27).

Answer:

• The multiplexer: DG408LE

• the selection of the analog input is done via GPIO6, GPIO12 and GPIO13

How can I access

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the Digital Inputs / Outputs from Codesys?

There is a tutorial which describes the "blinking lights" using Codesys

• https://revolutionpi.com/tutorials/beispiel-blinking-light-2/

I want to count rising edges with the

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Revolution Pi Compact module, is that possible?

Yes, look here:

• https://revolutionpi.de/forum/viewtopic.php?f=8&t=3062#p11153

What is the sampling rate or cycle time of the analogue inputs?

There is a discussion in the forum here, but it is in German

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• https://revolutionpi.com/tutorials/ein-ausgaenge-steuern-mit-picontrol-compact/

• https://revolutionpi.com/tutorials/ein-ausgaenge-steuern-ohne-picontrol-compact/

I want to read out an analog PNP sensor with Python

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– how can I do that?

Have a look at this tutorial:

• https://revolutionpi.com/tutorials/digitale-ein-und-ausgaenge-compact/?noredirect=en_US

Have a look at the BitMirror example:

• https://revolutionpi.de/forum/viewtopic.php?f=6&t=2535&p=9196&hilit=bitmirror#p9196

The original discussion is here:

• https://revolutionpi.de/forum/viewtopic.php?f=3&t=3020

Can the digital inputs work as counters?

No, this is not an integrated function of the RevPi Revolution Pi Compact.

Can the digital outputs be used for PWM?

No, this is not an integrated function of the RevPi Compact.

When I look at the /var/log/kern.log, i am seeing a flood of messages "piControl i/o: missed xx cycles". Why is this error? How can we stop this error?

https://revolutionpi.de/forum/viewtopic.php?f=6&t=2998#p10787 Revolution Pi Compact.

I want to connect

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RS-485 to PLC by I/O

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RS-485 at Pin P and N (not USB),

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what do I have to do?

Have a look at our tutorial

https://revolution.kunbus.com/tutorials/serielle-geraete-anschliessen-compact/

There are two different supply voltages

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– device and IO channels. Is there a sequence to be observed?

• No, the sequence does is not matterrelevant. However, external devices should only be connected in a de-energized state and checked for correct wiring before commissioning to avoid destruction.

• Connecting power supply (Compact) - Industrial Raspberry Pi

• Digital Inputs and Outputs (Compact) - Industrial Raspberry Pi

I want to set a GPIO pin high and I don't use piControl. Why does the pin always go low?

• The digital outputs are equipped with a watchdog. A watchdog is a component that monitors the functioning of other components in a system. In this case, the digital outputs must be rewritten at least every 9 milliseconds. If this does not happen, the watchdog sets the digital outputs to “low” to establish a safe state! As the system might have crashed.

• https://revolution.kunbus.com/tutorials/ein-ausgaenge-steuern-ohne-picontrol-compact/?noredirect=en_US

There is an undocumented interface on the

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Revolution Pi Compact, can this be?

The HDMI interface is present but is not considered a warranted capability, ; therefore we do not warrant or support the HDMI interface.

Can the

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Revolution Pi Compact be expanded, e.g. with I/O modules?

No, the RevPi Revolution Pi Compact is not expandable.

Can the

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Revolution Pi Compact handle measurements of negative Voltages?

No, the range is 0 - 10 V.

https://revolution.kunbus.com/revpi-compact/

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