rotork Mk3 Technical Manual page 115

2. Output Blocks
Setting the "Discrete Block Control" mode in the Transducer Block to multiple support
a/
and downloading more than one DO in the schedule.
Whilst all five DI blocks can be used in multiple support mode to give 40 DI states, only one DO
can be used. Downloading two or more DOs from the same actuator will result in the actuator failing
to respond to DO commands.
Setting the "Discrete Block Control" mode in the Transducer Block to multiple support
b/
and writing more than one actuator control command.
It is possible to send multiple DO commands to the actuator's output relays via a DO block, but
it is not possible to send more than one actuator control command, e.g. open, close or stop. Sending
two commands at the same time will result in the actuator failing to respond to either.
Setting the "Discrete Block Control" mode in the Transducer Block to single bit support
c/
and writing more than one actuator control command.
Sending more than one actuator control command, e.g. open, close or stop at the same time
will result in the actuator failing to respond to either. Sending a command and then sending another
counter command, without cancelling the first, will result in the actuator continuing with the first
command.
d/ Trying to operate the output relays with an LO alarm status present.
If the actuator has a monitor relay fault, any of its control blocks (AO or DO) being used in the
schedule will be put into an LO state and all commands via this block will be inhibited. This means not
just the actuator control but also the output relays which may be used for controlling other equipment
outside of the actuator. The same control inhibit function is true if the block is in an IMAN state
e/ Action on loss of comms settings.
There is a series of actuator parameters, accessible via the TB that, if enabled, can drive the
actuator to an end of travel limit, mid-travel position, or stop the actuator when host comms are lost.
These are parameters 56 to 58 in the TB.
There is also a standard FF parameter within the DO and AO blocks known as "Fault state to
value". If this is selected and the FF block goes into fault state, the value in the "fault state value
register" will be used by the function block. As an example, if the upstream block connected to the AO
block has problem this will put the AO block in fault state – if the fault state value is 50, then the
actuator will be sent to 50%.
If both of these features are enabled, make sure they are set to perform the same function.
f/ Fault state on restart
This is another FF feature. If this is selected, any time the block restarts it will take the fault state
value and use that until the block itself reaches CAS mode. This is NOT a fault state, it is just using
the Fault State value.
Publication PUB089-005-00_0618
Appendix
115 of 116