FC 122 - Digital Input / Cnet

The digital input/Cnet function code acquires a digital input from another module in a different node via Cnet. If the source node is a process control unit, the input must come from a digital exception report block (function code 45), a digital in/channel (function code 224), or a digital out/channel (function code 225). If the remote node is a network interface unit, the input must come from an analog report index. Updates are on an exception report basis. Segment control blocks in Harmony controllers specify exception report intervals.

 

To insure that the signal is successfully acquired from the Cnet, the digital signal generates a point quality flag. To test the quality of the signal, include a function code 31 in the configuration. The quality of the point cannot be used as an input to any other type of block. However, the output of the test quality block, representing the quality, can be used as an input to other analog processing blocks.  Refer to Appendix H, for a definition of point quality.  

 

NOTE: If a module utilizes an imported digital value from the loop in several instances in its configuration, the function blocks that utilize that digital value must be connected to only one digital input/Cnet block. Exception reports from the same (loop, node, module and block) address cannot be imported to more than one destination within a single module configuration.

 

Outputs:

Blk

Type

Description

N

B

Digital  output value, quality and alarm state

 

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

N

0

I

0 - 31

Source module address

S2

N

0

I

Note 1

Source block address

S3

N

0

I

0 - 250

Source node address

S4

N

0

I

0 - 250

Source loop address

S5

N

0

I

0 - 2

Input block type. Defines the type of remote block address that is being referenced:

0=function code 45

1=function code 224

2=function code 225

S6

N

0.000

R

Full

Spare

S7

N

0

I

Note 1

Spare

 

NOTES:

1. Maximum values are: 9,998 for the BRC-100, IMMFP11/12 and 31,998 for the HAC