I/O Blocks > Pulse Input (PIN) function block

Pulse Input function block execution

You select the manner of processing the pulse value by configuring the I/O selection and filtering parameters.

I/O Selection

When you configure the Pulse Input function block, you select the I/O channel associated with an pulse measurement by configuring the Device Signal Tag (DST) of the IO_IN parameter. You select the Device Tag and the parameter the PIN block accesses on that channel.

The valid channel parameter for IO_IN is:
  • FREQUENCY — The frequency of pulses on a pulse input channel (counts per second)

Simulation

To support testing, you can enable simulation. This allows the measurement value and status to be supplied manually or from another block.

During configuration, decide whether you want to enter the simulated value/status manually during operation or use a value/status from another block for the simulated value/status.

When the value is entered manually:

Note

Use the SIMULATE parameter to enter values manually and make sure SIMULATE_IN is not connected. If SIMULATE_IN is connected or a value is entered manually into SIMULATE_IN, the SIMULATE_IN value overrides the SIMULATE value.

When the value/status from another block is used:

Note

Do not enter a value for the SIMULATE_IN parameter. If you do and the status of SIMULATE_IN is not Bad: NotConnected, the manually entered value for SIMULATE_IN overrides any value you enter in SIMULATE.

Filtering

You apply filtering to the converted value (PV) by specifying the filter time constant (in seconds) in the PV_FTIME parameter. When you specify a value of zero, no filtering is applied.

Block Errors

The following conditions are reported in the BLOCK_ERR parameter:
  • Simulate active — Simulation is enabled and the block is using a simulated value in its execution.

  • Input failure/process variable has Bad status — The source of the block's process variable is bad. Indicates a hardware failure, a non-existent Device Signal Tag (DST), or a Bad status on the SIMULATE parameter.

  • Out of Service — The block is in Out of Service (OOS) mode.

Calculation of OUT

OUT equals PV and status when in Auto mode. The operator sets OUT when in Manual mode.

The DeltaV Multifunction card calculates the frequency of pulses in counts per second. Therefore, the block does not use scan rate in the calculation of OUT.

Calculation of PV

The Pulse Input function block's PV is calculated by frequency times pulse value times time units factor.

The DeltaV Multifunction card calculates the frequency of pulses in counts per second. Therefore, the block does not use scan rate in the calculation of PV.

Calculation of FIELD_VAL

The Pulse Input function block's FIELD_VAL is calculated as the percent value of PV within the range defined by OUT_SCALE.