I/O Modules - Inputs and outputs - Problem with spontaneously changing IO values

Issue

Values on inputs and outputs of the I/O modules change despite the value has not actually changed or the value is different from the actual one. Outputs do not activate despite the active state is on.

Possible solutions

• Problem with spontaneous changing of values on inputs and outputs

• No control over outputs

• Problem with pulses missed by SfAR-S-ETH

• Problem with wrong output values in Niagara

• Problem of immediate transition of digital output from high state to low state without providing a low signal

• Problem of outputs not activating despite active state on

Problem with spontaneous changing of values on inputs and outputs

Values of inputs and outputs change constantly and regularly.

Solution

1. Check if the Watchdog time is not too short. Communication has to be carried out more quickly than the set Watchdog parameter.

2. Switch off the Watchdog setting it to 0 and switch off the Default State option.

3. Check if the logic on the supervising controller is not overwriting values.

4. If the device has filters on the input, check if the are switched on.

5. Check if the byte order is set to 1032. If not, set it.

No control over outputs

Change of value is not executed on the output.

Solution

1. Check if the wiring is correct.

2. Update the firmware to the latest version. If the latest firmware has already been uploaded, reload it.

3. Check if the Watchdog time is not too short. Communication has to be carried out more quickly than the set Watchdog parameter.

4. Switch off the Watchdog, setting it to 0, and switch off the Default State option.

5. Check if the logic on the supervising controller is not overwriting values.

6. Check if the writing command is correct according to the type of output to be controlled.

   

Problem with pulses missed by SfAR-S-ETH

Devices connected to the module’s inputs generate pulses, which are visible in the iSMA Configurator but are not counted by the input counter.

Solution

1. Update the firmware to the latest version. If the latest firmware has already been uploaded, reload it.

2. Restore the device to factory settings and check if the problem persists.

3. Check if any of registers used to reset the counter (decimal address 960 for DI1, 961 for DI2, 962 for DI3, and 963 for DI4) is not set to 1.

Problem with wrong output values in Niagara

Output values automatically change to a different value than the setpoint despite the presence of a value at the in16 input in the Proxy Point Niagara block.

Solution

1. Check if the Watchdog value is not quicker than the communication frequency. It is possible that watchdog is overwriting output values if communication is not carried out for some time.

2. Check for a value stored in Fallback that should not be there.

3. Check if the Max Write Time value is higher than 0. This setting will force writing command after a certain amount of time.

4. Set the Max Write Time value in compliance with previously set parameters (e.g., Watchdog) so that values get constantly updated.

In the iSMA Configurator, after connecting the I/O module and switching it to online, Watchdog settings are available in the Digital Outputs tab.

5. Check the COV configuration and the unsolicited COV settings.

Problem of immediate transition of digital output from high state to low state without providing a low signal

After a very short period of time, digital outputs spontaneously switch to state 0 immediately after state 1 is activated.

Solution

1. Check if the Watchdog time is not set to a too short value, for example, 1 second.

2. Check if the device’s firmware is up to date.

3. If the latest firmware has already been uploaded, reload it.

4. Restore the device to factory settings and check if the problem persists.

5. Check if the application logic is not overwriting values on digital outputs registers.

6. Check that the controller and module have the same ground going from the power supply to G0.

7. If possible, swap the problematic devices and see if the problem occurs on another module.

Problem of outputs not activating despite active state on

The outputs do not react to active state.

Solution

1. Set the Watchdog time to 0.

2. If the module is equipped with hand switches, check if they are set to Auto.

3. Check if there is no other supervising controller on the bus, which could overwrite values.

4. In Niagara (or other corresponding system), set the Max Write Time value in BACnet tuning policy in compliance with an expected system functionality and according to the type of output, for example, to 30 seconds.

   

5. Update the firmware to the latest version. If the latest firmware has already been uploaded, reload it.

6. Restore the module to factory settings.