National Instruments FP-3000 - Manual (Page 56)

Chapter 4 Block Reference
FieldPoint FP-3000 User Manual 4-4 www.ni.com
DO (Discrete Output)
The DO block writes to a discrete output channel. This block supports
cascade initialization to allow upstream control blocks to determine the
current state of the process before assuming control. It also has a faultstate
behavior that allows the block to react if communications fail between
itself and the upstream block.
CDO (Complex Discrete Output)
The CDO block serves the same purpose as the DO block and adds a
number of parameters to support interlocking at three levels of priority.
LOG (FieldPoint Log Block) (FP-3000 Specific)
The LOG block contains a log of error conditions and events detected by
the device as it operates.
STAT (FieldPoint Statistics Block) (FP-3000 Specific)
The STAT block contains a set of parameters that can be used to examine
how the device is performing. It contains statistics describing the
performance of local function blocks and the network interface.
Table 4-1. CDO Block Interlock Priorities
Input
(Descending Priority) Notes
Safeguard Close
(
SAFEGUARD_CL )
Safeguard Close takes priority over any other interlock input.
Safeguard Open
(
SAFEGUARD_OP )
Safeguard Open takes priority over every other interlock input and is
used to force the block to an open state (
Discrete_State_1 ).
Binary Open/Close
(
BINARY_OP/BINARY_CL )
BINARY_OP only functions when ENABLE_OP has a value of
Discrete_State_1 . BINARY_CL only functions when ENABLE_CL
has a value of Discrete_State_1 . If both BINARY_OP and
BINARY_CL are set and enabled, neither one takes effect.
Operator Command
(
OP_CMD_CXO )
OP_CMD_CXO is a contained bit string parameter that has a bit for
Open and a bit for Close. Open only functions when ENABLE_OP has
a value of Discrete_State_1 . Close only functions when
ENABLE_CL has a value of Discrete_State_1 . If both Open and
Close are set and enabled, neither one takes effect.