Error messages are stored in input word 5 (the 3x +4 register). This section explains how to interpret the bits in that register.
This diagram explains the error message displayed by each bit. A value of 1 indicates the error has occurred
This error occurs when the I/O base has not yet received valid parameters or has just received parameters for the first time and is checking them.
Invalid Parameters (Bit 9)
This error occurs when the I/O base refuses one or more invalid parameters. The base will continue working with the old parameters until it receives a complete set of valid parameters.
Overrange Indication (Bit 12)
This error occurs when the I/O base detects an overrange analog input value. The threshold is range-dependent.
Underrange Indication (Bit 13)
This error occurs when the I/O base detects an underrange analog input value. The threshold is range-dependent.
Broken Wire Detection (Bit 14))
Broken wire detection is possible for the 4 ... 20 mA range. In this case, a current signal that is less than 2 mA on one of the inputs is detected as a broken wire. The input word of that channel returns the value -32,768.
In the 1 ... 5 VDC range, broken wire detection is correctly seen as undervoltage detection. A voltage of less than 0.5 VDC on one of the input channels is recognized as broken wire. The input word of that channel returns the value -32,768.
In case of a broken wire, the input floats and bit 14 is not set in all cases. A reliable broken wire detection is only possible if a resistor is wired in parallel to the input terminals. This resistor will discharge the input capacity and broken wire detection will be available.
The value of this resistor depends on internal resistance of the sensor. Values too low might influence the input signal and values too high lengthen the time for broken wire detection. Normally, values of less than 100 kOhm are appropriate.
This error occurs when the I/O base detects a short circuit on a discrete output.
