Function block parameters > Option bitstring parameters

I/O options

The I/O options parameter (IO_OPTS) allows you to select how the I/O signals are processed. You can set I/O options in Manual or Out of Service mode only. The following are the I/O options in the DeltaV system:
  • Low Cutoff — When the converted input value is below the limit specified by the LOW_CUT parameter and Low Cutoff is enabled (True), a value of 0.0 is used for the converted value (PV). This option can be useful with zero-based measurement devices such as flow meters.

  • Use PV for BKCAL_OUT — Changes the BKCAL_OUT value to the PV value. When the Use PV for BKCAL_OUT option is not enabled (False), the BKCAL_OUT value is the working setpoint value.

  • Target to Man if Fault State activated — Set the target mode to Man, thus losing the original target, if Fault State is activated. This latches an output block into the manual mode.

  • Use Fault State value on restart — Use the value of FSTATE_VAL(_D) if the device is restarted, otherwise use the non-volatile value. This does not act like Fault State, it only uses the value of FSTATE.

  • Fault State to value — The output action to take when fault occurs. (0: freeze, 1: go to preset value)

  • Increase to Close — Indicates whether or not the output value is inverted before it is communicated to the I/O channel.

  • SP-PV Track in LO or IMan — Permits the SP to track the PV when the actual mode of the block is LO or IMan. SP-PV Track in Man takes precedence over SP-PV Track in LO or IMan. SP-PV Track in Man must be enabled in order for SP-PV Track in LO or IMan to track when Target mode is MAN.

  • SP-PV Track in Man — Permits the SP to track the PV when the target mode of the block is Man.

  • Invert — Indicates whether the discrete input should be logically inverted before it is stored in the process variable. A discrete value of zero (0) will be considered to be a logical zero (0) and a non-zero discrete value will be considered to be a logical one (1). For example, if invert is selected, the logical NOT of a non-zero field value would result in a zero (0) discrete output, and the logical NOT of a zero field value would result in a discrete output value of one (1).

Note

IMan is not possible in an I/O block.