ClearCore I/O Expansion Board

Overview

For applications that require additional digital I/O pins, ClearCore may be linked with up to 8 ClearCore I/O Expansion Board (CCIO-8) modules. The ClearCore software package provides a
CcioBoardManager that interfaces with and controls the CCIO-8 link. Each CCIO-8 module has 8 CcioPin connectors that may be individually configured as a digital input or output, providing up to 64
additional digital I/O connectors.

The CcioBoardManager uses SPI to communicate to the CCIO-8 modules. The CCIO-8 modules are chained together and attached to either the COM-0 or COM-1 connectors. When a COM port is opened in CCIO
mode, ClearCore automatically detects how many CCIO-8 modules are in the chain. The CcioBoardManager will then periodically refresh the input and output CcioPin connectors as part of the ClearCore
system's background processing.

Wiring and Initialization

• Connect 24V power to the PWR terminal block on each CCIO-8 module (next to CCIO-8 pin 3). 24V power may be supplied three ways: from a source independent of the ClearCore, by connecting to any
  of the main ClearCore board's I/O connectors, or by connecting to an I/O connector of a CCIO-8 earlier in the chain.
• Check that the Power OK LED (next to CCIO-8 pin 4) on each CCIO-8 module is on.
• Connect either the COM-0 or COM-1 port from the ClearCore to the COM_IN port on the CCIO-8 module with an RJ45 cable.
  • If multiple CCIO-8 modules are needed, create a chain by connecting the COM_OUT port of CCIO-8 module (N - 1) to the COM_IN port of CCIO-8 module N. Repeat until all of the
    modules (up to 8) are linked together.
• Check that the LED in each connected COM_IN and COM_OUT port is on.
  • The LED in the COM_OUT port on the final CCIO-8 module in the chain should be off.
• Put the ClearCore COM connector in CCIO mode using SerialDriver's SerialDriver::Mode() function then open the port. Calling PortOpen() in CCIO mode will call
  the CcioDiscover() function automatically in the background.

  // Set COM-1's mode to be the port controlling a CCIO-8 link
  ConnectorCOM1.Mode(Connector::CCIO);
  ConnectorCOM1.PortOpen();

• Verify that the number of discovered CCIO-8 modules matches the number of modules that were wired.

  // Are the CCIO-8 modules properly wired and communicating?
  if (CcioMgr.CcioCount() != myExpectedModules) {
      // The link size is wrong, do something
  }

• The CCIO-8 modules in a link are represented by the letters A-H. The CCIO-8 module that is connected directly to the COM port is addressed using ClearCorePins CLEARCORE_PIN_CCIOA0 through
  CLEARCORE_PIN_CCIOA7. The next CCIO-8 module in the chain uses ClearCorePins CLEARCORE_PIN_CCIOB0 through CLEARCORE_PIN_CCIOB7, and so on.

Configuring CCIO-8 Pins

• Each pin on the CCIO-8 modules can be independently configured as either a digital output or digital input.

  // Set CCIO-8 board A, pin 0 to output mode and assert the output.
  CcioPin *ccioA0 = CcioMgr.PinByIndex(CLEARCORE_PIN_CCIOA0);
  if (ccioA0 != nullptr) {
      ccioA0->Mode(Connector::OUTPUT_DIGITAL);
      ccioA0->State(1);
  }
  // Set CCIO-8 board B, pin 1 to input mode and read the current value.
  bool value = false;
  CcioPin *ccioB1 = CcioMgr.PinByIndex(CLEARCORE_PIN_CCIOB1);
  if (ccioB1 != nullptr) {
      ccioB1->Mode(Connector::INPUT_DIGITAL);
      value = ccioB1->State();
  }

Operation

• The CcioBoardManager periodically refreshes the CcioPin values as part of its background processing. The refresh rate varies depending on the length of the CCIO-8 chain.
  • 1-2 CCIO-8 modules: Refresh at SampleRateHz
  • 3-4 CCIO-8 modules: Refresh at SampleRateHz / 2
  • 5-6 CCIO-8 modules: Refresh at SampleRateHz / 3
  • 7-8 CCIO-8 modules: Refresh at SampleRateHz / 4
• CcioBoardManager refresh cycle processing operations:
  • Ensure that the previous SPI transfer is complete.
  • Toggle the SPI Slave Select line to activate the outputs that were sent in the previous refresh cycle and latch a snapshot of the inputs.
  • Check the integrity of the previous input data transfer.
  • Perform input pin filtering.
  • Prepare the current output data to transfer.
  • Initiate a background SPI data transfer.
• The CcioBoardManager monitors the status of the CCIO-8 communications to ensure that the link is maintained.
  • If all or some of the CCIO-8 link goes offline the StatusManager::StatusRegister::CcioLinkBroken bit will be raised.
  • The CcioBoardManager automatically attempts to re-establish a broken CCIO-8 link through the Rediscover feature. The CCIO-8 Rediscover feature is enabled by default, but it may be disabled
    if link-breaks and rediscovers need to be manually controlled.

    See also

    CcioBoardManager::CcioRediscoverEnable