FC 121 - Analog Input / Cnet

The analog input/Cnet function code acquires an analog input from another module in a different node via Cnet. If the source node is a process control unit, the input must come from an analog exception report block (function code 30), an analog in/channel (function code 222), or an analog out/channel (function code 223). 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. The executive block for the controller module and the segment control block for the harmony controllers modules specify the exception report intervals.

 

To insure that the signal is successfully acquired from Cnet, the analog 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 processing blocks.  Refer to Appendix H, for a definition of point quality.  

 

Outputs:

Blk

Type

Description

N

R

Analog 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 30

1=function code 222

2=function code 223

S6

N

0

I

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