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Publication 1757-RM810A-EN-P - May 2002

3-12 Functional Blocks

DOCHANNEL

PWMCHANNEL

Description Generates status output (0 or 1), pulsed output (ON or OFF) for specified pulse time based on origin of input and

parameters.

Function • Brings SO or PO from connected blocks and stores value in an associated IOM block.

• Sets INITVAL parameter to appropriate value based on echo data.

• Stops SO if INTREQ is TRUE

• Sets INITREQ to TRUE value if DOC or IOM block is inactive or a communications error occurs.

• You can configure PO to be Direct or Reverse by connecting ONPULSE or OFFPULSE pin.

Inputs Only one control block can interface to this block.

Outputs Digital (Boolean) value or pulsed (real) value.

Associated

Block

Prior to loading, block must be “associated” with 1 channel of corresponding IOM block that interfaces with physical

DO hardware module at execution runtime.

Parameters BACKCALCOUT

BADCODE

DEBUG

DOMSO

DOTYPE

EXECCOUNT

FETCHMODE

FREEZETIME

INITREQ

INITVAL

IOCNUMBER

IOCSTATE

IOCTYPE

IOMCONN

LASTSERIAL

NOFIELDPWR

NOLOAD

OFFPULSE

ONPULSE

ORDERINCM

SHORT

SOSOURCE

UPDATOPT

VERIFYLOST

Description Provides a pulse width modulated output signal for operating final control elements in combination with a DO

Module.

Function • Brings OP data from connected block and stores data in an associated IOM block.

• Sends out a pulse based on the configured pulse width period (PWMPERIOD) with its duty cycle determined by the

OP data.

• Sets INITVAL parameter to appropriate value based on echo data.

• Assigns safe value if status parameter is BAD or UNCERTAIN.

• Sets INITREQ to TRUE (ON) value if CM containing PWMC block or IOM block is inactive or a communications error

occurs. If communication fails, the pulse function terminates. So, be sure you select the proper SHED VALUE for

the DOM channel to reflect the desired inactive digital state.

Inputs OP value from another block. Typically, output in 0 to 100% from a PID block, which indicates the proportion of time

period that the output will be turned on.

Outputs Pulsed (real) value