I/O Blocks > H1 Carrier Fieldbus Multiple Discrete Output (FFMDO) function block

H1 Carrier Multiple Discrete Output function block execution

The H1 Carrier Multiple Discrete Output function block determines its setpoint and sets the output.

Setting the Output

The block first must determine its setpoint. Normally, the block is used in Cas mode, and the cascade input value (CAS_IN_D) becomes the setpoint (SP_D). In Automatic (Auto) mode, the block disconnects CAS_IN_D and allows a manual entry to change the value of SP_D. In Man mode, OUT_D can be entered manually.

Note

CAS_IN_D should always be an 8-bit integer value.

I/O Options

You select the I/O options by using the IO_OPTS parameter:

  • SP-PV Track in Man — This option is enabled (True) as a default. SP_D becomes a copy of PV_D when the block's target mode is Man. A manually entered SP_D value is overwritten on the block's next execution cycle. This can prevent a state change when transitioning from Man to Auto mode. You can disable this option in OOS mode only.

  • SP-PV Track in LO or IMan — When this option is selected, SP_D becomes a copy of PV_D when the actual mode of the block is Initializing Manual or Local Override.

    The block goes to IMan mode under the following conditions:

    • No DO card or the wrong card is present.

    • Communication with the H1 carrier is bad.

    • The transducer block in the H1 carrier is in OOS mode.

    The block goes to LO mode when the fault state is active.

  • Tgt to Man if Fault State Active — This option causes the target mode of the block to become Man when the fault state is active. Any of the following conditions causes the fault state to be active:

    • The actual mode of the block is Cas and the status of CAS_IN_D is BAD.

    • The actual mode of the block is Cas, and the substatus of CAS_IN_D is Initiate Fault State.

    • The fault state is set manually in the resource block in the H1 carrier.

  • Use Fault st val on Restart — This option causes OUT_D to have the value of FSTATE_VAL_D on a restart (that is, when the carrier is powered up).

  • Fault State to value — This option causes OUT_D to have the value of FSTATE_VAL_D when the fault state is active. This occurs FSTATE_TIME seconds after the fault state is detected if the condition still exists. When the option is not selected, OUT_D keeps its value when the fault state is active.

  • Use PV for BKCAL_OUT — This option results in the value of BKCAL_OUT_D being that of PV_D. Normally, BKCAL_OUT is the value of SP_D.

  • Invert — When this option is enabled (True), OUT_D becomes an inverted copy of SP_D. When this option is not enabled (False), OUT_D is a straight copy of SP_D. Inversion is done on a bit by bit basis.

Note

You can set I/O options in Out of Service mode only.

Simulation

When SIMULATE_D is not enabled and the mode is not Out of Service (OOS), the value of OUT_D is sent to the hardware. When SIMULATE_D is enabled, the status of OUT_D is forced to Good, regardless of the condition of the hardware. In addition, READBACK_D and PV_D take on the value and status of SIMULATE_D.

Block Errors

The following conditions are reported in the BLOCK_ERR parameter:

  • Simulate active — SIMULATE_D is enabled; therefore, PV_D is not real.

  • Input failure/process variable has Bad status — The source of the block's process variable is bad. For the FFMDO block, this might indicate a hardware failure or a Bad status on the SIMULATE_D parameter.

  • Output failure — The output hardware is Bad.

  • Out of Service — The block is not being processed.