Discrete Output Blocks - rotork Mk3 Technical Manual

6.6

Discrete Output blocks

Discrete (Open/Stop/Close) control of the actuator, or mixed discrete and analogue position control is
possible provided the FF CP card is set up correctly in the Transducer block and the correct settings
are applied. There are 4 Discrete Output (DO) blocks in the FF card that allow the actuator to be
moved. In addition, when the optional relay output board is fitted, the status of the four relays may be
controlled.
As with the DI blocks, the DO blocks make use of all 8 bits within each block. The actuator will
respond to values between 0 and 255 sent via one DO block when multiple support is selected, or to
the value of the first bit (0/1) when single bit and one or more DO blocks are used. Single or multiple
bit discrete use is selected using parameter 70 in the transducer block. When multiple bit support is
selected only one of the DO blocks may be used for discrete control. If control using DO 4 is adopted it
is necessary to set the mode for this block using parameter 65 in the transducer block.
CAS_IN_D
SETPOINT
RCAS_IN_D
Fig 6.9: Discrete Output Function Block
On installing the card, the following settings will apply:

The output connections to the Transducer block are fixed and in place.

The Mode control is standard (Auto, Man, LO, OOS).

When the actuator Local/Remote selector is not in the Remote position the block will
adopt LO mode.

The IO_OPTS should be set to PV_D for BKCal_Out_D.

DO 1 is channel number 9 (this must not be changed).

DO 2 is channel number 10 (this must not be changed).

DO 3 is channel number 11 (this must not be changed).

DO 4 is channel number 12 (this must not be changed).
Where multiple support is selected, only one DO should be set to Auto. All other DO blocks must be
set to Man or OOS.
DO
BKCAL_OUT_D
RCAS_OUT_D
OPTIONAL
INVERT
OPTIONAL
INVERT
Publication PUB089-005-00_0618
Actuator Input Output Signals
OUTPUT
SIMULATE
PV_D
READBACK_D
Out_D
(Transducer)
Channel
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