Rockwell Automation 1788-CN2FF ControlNet-to-FOUNDATION Fieldbus H1 Linking Device User Manual - Manual (Page 39)

1788-6.5.1 - January 1999
Using the ControlNet-to-FOUNDATION Fieldbus H1 Linking Device 4-13
In the second configuration, shown in Figure 4.9, the controller provides the
necessary mode handshake for cascade initialization of the DO block. In
this case, you connect CN_OUT_D
x of the MDO block to the CAS_IN_D
parameters of the DO block, and the BKCAL_OUT_D parameter of the DO
block to BKCAL_IN
n of the MDO block. Note that there is a strict ordering
relationship between the CN_OUT_D x and CN_BKCAL_IN_Dx
parameters of the MDO block, that is, CN_BKCAL_IN_D0 is associated
with CN_OUT_D0, CN_BKCAL_IN_D1 with CN_OUT_D1, and so on.
You can connect the MDO block to any parameter that is a byte value and
status combination. In other words, you can bring values from a PLC
processor to any function block. The MDO block is not limited to
interfacing with DO function blocks.
ControlNet Discrete Output Objects
The linking device creates an instance of a ControlNet DO object for every
wired channel in the MDO block instances. Each instance of the ControlNet
DO object has the attributes shown in Table 4.D.
Note that BkCalStatus is created only when the controller is capable of
participating in the CAScade initialization handshake, that is, when the
BKCAL_OUT_D of the DO block is wired to a BKCAL_IN
x parameter of
the MDO block.
Only Value, CNStatus, casInstatus, ReadBack, and TagDesc are created
when an MDO channel is connected to something other than a DO function
block CAS_IN_D parameter.
Table 4.D ControlNet Discrete Output Object Attributes
Attribute
Number Name Type Access Initial Value Remarks
3 Value Boolean Set 0 This is written from the ControlNet side.
4 CNStatus Boolean Set Bad ControlNet status. 0-Good; 1-Bad.
6 FailStateValue uint8 Set 0 The linking device writes the value to the DO
block when this attribute is changed by the
controller.
151 TagDesc String Get As configured Tag of the Fieldbus function block that this
object instance represents.
152 FailstateTime Float Set 0 The linking device writes the value to the DO
block when this attribute is changed by the
controller.
153 ReadBack uint8 Get 0 This represents the BKCAL_OUT _D value
from the DO block.
154 BkCalStatus uint8 Get Bad:Not-
Connected This represents the status of the Readback
attribute.
155 casInstatus uint8 Set Bad:Not-
connected This represents the status of the CAS_IN_D to
the DO block.