FC 27 - Analog Input (COM & CLC Modules)

The analog input function code acquires analog inputs from termination units for controller modules. This function acts only on controller module fixed inputs. Analog input one will always be found in block 201, analog input two in block 202, etc. To modify this function, specify a fixed analog input block number (201-204). The specifications define the zero and span values, expressed in engineering units. If a span is 0.000, the input is unused.

 

To insure that the signal is successfully acquired, the analog signal generates a point quality flag. To test the quality of the signal, include a function code 31 (test quality) block in the configuration. The quality of the point cannot be used as an input to any other type of block. The analog output value can be used as an input to any analog processing block.

 

Outputs:

Blk

Type

Description

201

R

Controller fixed analog input 1 and quality

202

R

Controller fixed analog input 2 and quality

203

R

Controller fixed analog input 3 and quality

204

R

Controller fixed analog input 4 and quality

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

N

0.000

R

Full

Signal Zero in Engineering Units

S2

N

0.000

R

Full

Signal Span in Engineering Units

 

 

27.1  Applications

 

Figure 27-1 shows the use of a function code 31 block to test the quality of the output from the function code 27 block.